New insights on the phylogeny of the Lytoceratoidea (ammonitina) from the septal lobe and its functional interpretation

Article (PDF Available)inRevue de Paleobiologie 29(1):1-156 · January 2010with 973 Reads
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Abstract
Lytoceratites together with Phylloceratites are often described as “conservative”. However, the origin and monophyly of lytoceratid ammonites as well as their role in the evolution of all ammonites is under constant debate. In this work, the Lytoceratoidea investigated on generic level for the presence of a septal lobe. Included into this investigation is the verification of relevant literature and the registration of the collected literature in a database system. Furthermore material from public and private collections was studied. The investigation reveals that all Lytoceratoidea are characterised by the presence of a septal lobe which constitutes their monophyly (cp. Arkell et al., 1957). The septal lobe represents a consistent morphological character that appeared in the lowermost Jurassic and is present in the uppermost Cretaceous members of Lytoceratoidea. It was noticed that the septal lobe appeared earlier in ontogeny and was stronger developed in most of the stratigraphical younger representatives compared to Jurassic members (acceleration). In addition, further characters have been investigated and tested for their phylogenetic significance. It turned out that most of these characters e. g. whorl section, course and number of constrictions are homoplastic or highly variable within one genus. Finally, six characters (septal lobe, parabolic ribs, fimbriation, shape of adult lateral lobe, primary suture, jaw type) have been kept for stratocladistic analyses. With this method the phylogeny within the Lytoceratoidea was enlightened as far as possible. Within the family Lytoceratidae five monophyletic subfamilies are retained : Ectocentritinae, Pleuroacanthinae, Lytoceratinae, Alocolytoceratinae and Megalytoceratinae. The monophyly of the second family Tetragonitidae is based on the distribution of the quinque- and sixlobate primary suture line and the development of a rhynchaptychus (Engeser & Keupp, 2002). Within the Tetragonitidae two subfamilies (Gaudryceratinae and Tetragonitinae) and one tribus Gabbioceratini are retained. This work has been the first critical-systematical review for the whole group within the last forty years. As a main result of this investigation fifteen genera have been excluded from Lytoceratoidea, seventeen genera have been regarded as junior subjective synonyms. A sexual dimorphic couple is presented for Anagaudryceras (M) and Anagaudryceras (Zelandites [m]) for the first time in addition to the two well known of Lytoceras (M). Thirty genera have been retained as valid lytoceratid taxa. For some genera e. g. Lobolytoceras and Protetragonites the stratigraphic distribution has been extended significantly. “Trachyphyllites” costatus is included into Analytoceras hermanni and represents a typical Lower Jurassic lytoceratid member. It appears that the Lytoceratoidea are derived from psiloceratids at the Triassic-Jurassic-boundary as already stated by Guex (1987). The author assents the statement of Guex (1987) and regards the Lytoceratoidea as members of Ammonitina. Tetragonitidae are derived from Protetragonites. Both taxa develop non-fimbriate ribs in contrast to contemporary lytoceratids. Protetragonites fraasi from the Oxfordian (Upper Jurassic) represents the oldest member of that genus. Judging from the two characters sixlobate primary suture and septal lobe, discussed above, Lytoceratoidea represent the most advanced ammonoid group. In the second part of this thesis the functional significance of the septal lobe was investigated. It was planned to calculate the ratio of chamber volume against its surface. For this purpose a Gaudryceras specimen in hollow preservation was scanned using computer tomography at the “Bundesanstalt für Materialforschung und -prüfung” (Berlin). The ammonite was digitalised at “Konrad-Zuse- Institut” (Berlin) using AM IRA®. Unfortunately, the resolution was too low for the project. The positive effect of the ratio of chamber volume against its surface caused by the septal lobe can therefore only be assumed. It is supposed that the septal lobe increases the efficiency of the hydrostatic apparatus.
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1661-5468
VOL. 29, N° 1, 2010

1 RuhrUniversitätBochum,FakultätfürGeologischeWissenschaften,InstitutfürGeologie,MineralogieundGeophysik,
FachrichtungPaläontologie,Universitätsstrasse150,HausNA,Etage01Raum136,44801Bochum
 E-Mail:Rene.Hoffmann@rub.de
RevuedePaléobiologieGenève
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
engeser keupp

    
               Anagaudryceras  
AnagaudrycerasZelanditesLytoceras
  Lobolytoceras Protetragonites 
Trachyphyllitescostatus Analytocerashermanni  
guex

      guex         
 Protetragonites    Protetragonitesfraasi



  Gaudryceras  
     

  




            


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             
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              
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 
 
 
 
 
 
 
 
 
 
 neumAyr
 spAth
  EctocentritesCAnAvAri
  HolcolytocerasspAth
  AdnethicerasWiedmAnn
  PeltolytocerasspAth
  GalaticerasspAth
 hyAtt
  PleuroacanthitesCAnAvAri
Arkelletal.

                

              
             
       
            
         
              
engeser  keupp   
          

     
Derolytoceras  Trachylytoceras  Lytoceras      Anagaudryceras
AnagaudrycerasZelandites
      Lobolytoceras  Protetragonites    
TrachyphyllitescostatusAnalytocerashermanni
 guex

guex

Protetragonites
       Protetragonites     Protetragonites fraasi 
   


           Gaudryceras    



   



 
  EolytocerasFrebold
  AnalytocerashyAtt
 neumAyr
  Lytocerassuess
  ZaghouanitesrAkúsguex
  PtycholytocerasspAth
  LobolytocerasbuCkmAn
  ProtetragoniteshyAtt
 spAth
  AlocolytocerashyAtt
  PleurolytocerashyAtt
 spAth
  MegalytocerasbuCkmAn
  PerilytocerasrulleAu
  NannolytocerasbuCkmAn
 hyAtt
 spAth
  EogaudrycerasspAth
  Anagaudrycerasshimizu
  ParajaubertellamAtsumoto
  Gaudrycerasde grossouvrekossmAt
 breistroFFer
  GabbiocerashyAtt
  JauberticerasJACob
 hyAtt
 TetragoniteskossmAt
 KossmatellaJACob
 ArgonauticerasAnderson
 TakahashiamAtsumoto
 PseudophylliteskossmAt
 SaghalinitesWright & mAtsumoto
 
 AsapholytocerasspAth
 BaltzeritesrAkúsguex
 BouhamidocerasdubAr
 CarinolytocerasWiedmAnn
 CastanyicerasrAkúsguex
 ExomilocerasWiedenmAyer
 Fucinitesgugenberger
 Gorgheicerasventuri & Ferri
 KericseritesgéCzy & meister,
 LytoconitesWiedmAnn
 LytotropitesspAth
 Pictetiauhlig
 Tayloricitesguex
 TragolytocerasspAth
 Villaniatill
 
 
 
 
 
 
 
 

 
       




  Arkellet al.,    
      
 

  
       
 
       
donovAn
       

  zittel     
 


  hyAtt, buCkmAn  spAth 

  

        
  




sChindeWolF
    
   WiedmAnn 
     
drushChits
& mikhAilovA   
  
      
      
spAth
 spAth  
rAkús   venturi & nAnnArone
  breistroFFer  
 venturi & Ferri  
breistroFFer   spAth 
venturi & bilottA
WiedmAnnArkell etal.

       

      
    


     
       
sprey
      
    

    Lytoceras  Phylloceras
Ammonitesbruguieresuess
   linné
 
      
 l. v. buCh     neumAyr
        
   Lytocerassuess 
 Phyllocerassuess, 1865    
     
       
        

      
        
        
sAlFeld        
WiedmAnn
    
        
sAlFeldsChindeWolF
WiedmAnnbesnossov
&mikhAilovA
  
 kleinet al.,    diener
       
      

      
rulleAurAkúsdommergues
      

guex
       
      
 
 

 

 

 
       

spAthspAth
spAth neumAyr
 spAth   hyAtt
spAth
hyAtt
guex     guexet al. 
      
Rhacophyllites   Eopsiloceras

      
tAylor  hillebrAndt  bourillotet
al.,        Arkellet al.
 sChindeWolF    
      
        
     Wrightet al.,
shevyrev


 
     

       

  

       
       
CeCCA & rougetkorn,
 lAndmAn,  monks   moyne
& neige  rouget  rouget, neige &
dommerguesneigeetal.


       
      
     


      
       
       
       
        
         
       
       





  
      
Arkelletal.


      
   
       
     sChindeWolF, 
sAlFeld
Arkelletal.      

  WiedenmAyer   



      
       
        
 

 
     
  
        
      
     
        
        
nAgAo & sAito



      
    


        
  




          
         
       
         
        
 
  

       
         

 
       
hoFFmAnn & keupp
  


      
      

  
henderson
        
       
 

  
    
  
          
        
          

          
  
   
       
     

  


 drushChits & mikhAilovA


   
        
          
        
 

     drushChits & mikhAilovA
      

         
 LobolytocerasdenCkmAnn   
  
drushChits & mikhAilovA



         




WiedmAnn
Gaudryceras     
   shigetA   
        
        
      
      

         
  


      Analytoceras

      
         

     
        
    
      
CeCCA & rouget  
       
       
      
      
         
Pseudophylliteshenderson

       

  
        
      
mCnAmArA

       
        


         
     
 Lobolytocerascostellatum

Eogaudryceras

         


EctocentritesEolytocerasPleuroacanthites

Lytoceras
      
       


GabbiocerasJauberticeras
      Saghalinites

          
 
  

        

      
Pseudophyllites Gaudryceras    

        
 hölder       
         


 hölder       



d’orbigny        
       Lytoceras
eudesianum       
Quenstedt  
   Kossmatella ventrocincta  
F. A. Quenstedt      
deslongChAmpsLytoceras
eudesianum     d’orbigny  
Quenstedt
  deslongChAmps    

        uhlig


yAbe

      
       
  sAlFeld   
        
        
 nAgAo & sAito    
        
Gaudryceras Pseudophyllites  Lytoceras  
Kossmatella Anagaudryceras,  Protetragonites
    Gaudryceras   

        
        
   Wedekind     

WiedmAnn
   


 

     
      
        

       
WestermAnn   kennedy & CobbAn
heWitt & WestermAnn

        
      


  
  
neWell 
       
       
mutvei      
       
kuliCki &
mutveikuliCki, WeitsChAt & bAndel
sAunders
     
        


      

seilACher
& lAbArberA     
seilACherhendersonebel
     
         
WArd

 dAniel etal. 

keupp
      
     spAth   
       


      
 buCklAnd  oWen  zittel 
pFAFF  nAgAo & sAito  WestermAnn
    heWitt & WestermAnn
seilACher  kennedy & CobbAn 
hAssAn etal.,  


pFAFF
  
reyment teiChert
leWy
 
        
leWy

       
  
       


    

         
       

  



    WestermAnn   
        
      
   hölder   
WestermAnn      

    
        
    seilACher
     
hölder  
       
 Lytoceras seilACher   
      
      
      

        

henderson

       






      

      

ActaGeologicaPolonica, Afri-
can Natural History, Alcheringa, Ameghiana, Annales
dePaléontologie,AnnalesoftheSouthAfricanMuseum,
Association of Australian Palaeontologists Memoirs,
BeiträgezurPaläontologie(ÖsterreichUngarns),Berin-
geria,BulletinoftheBritishMuseum(NaturalHistory),
BulletinoftheNationalScienceMuseumTokyo,Series
C,CretaceousResearch,DocumentsdesLaboratoiresde
GéologiedeLyon,DokladyAkad.NaukSSSR,Eclogae
GeologicaeHelvetiae,FossiliumCatalogus,Fossilsand
Strata, Geobios (Mémoire Spécial), Geologica Hunga-
rica,GeologicaRomana,GeologicaetPalaeontologica,
HistoricalBiology,JournalofPaleontology(Memoirs),
Journal of Systematic Palaeontology, Kaupia, Lethaia,
MémoiresdeGéologie(Lausanne),MémoiresdelaSo-
ciétéGéologiquedeFrance(N.S.),MemoirsoftheFac-
ultyofScienceKyushuUniversitySeriesD,Mitteilungen
derBayerischen Staatsammlung für Paläontologie und
historischeGeologie,NeuesJahrbuchfürMineralogie,
Geologie und Paläontologie (Abhandlungen), Novi-
tates, Palaeontographica A, Palaeontologica Africana,
Palaeontologia Polonica, Paläontologische Zeitschrift,
Palaeontology, Palaios, Paleobiology, Paleontological
Journal,PaleontologicalResearch,PhilosophicalTran-
sactionsoftheRoyalSocietyofLondonB,Smithsonian
ContributiontoPaleobiology,Special PapersinPalae-
ontology,TransactionsandProceedingsofthePalaeon-
tological Society of Japan, Travaux du Laboratoire de
GéologiedelaFacultédesSciencesdeLyon(Ancienne
Série, Nouvelle Série), Tübinger Geowissenschaftliche
Arbeiten,ReiheA,ZapadneKarpatyseriePaleontology,
Zitteliana.
       
  
    
    
   
   
    
      
      


      hillebrAndt
   keupp   berWAld
moosleitner
     
       
     
      
       


       

       

 
 
 
 
 
      
          

 
 

 
 

 
 

 
 
 
 
 
 
         

 
 

 
 
 
 
 

 
 

        



 

 
 


         
      
       


       
    sChindeWolF  
      

      
      
    roderiC & pAge 
 
WiedmAnn
      sChindeWolF 
WiedmAnn & kullmAnn,venturi & bilottA
venturi & nAnnArone


    sWoFFord 
goloboFF etal.,mArCot
& Fox

 goloboFF et al.,   
      nixon, 
       

       
      
     
        
mArCot & Fox
     
 smith    
       
       
       
       
  bodenbender & Fisher 
 estAbrook & mCmorris  Fox et
al.mAkoviCkymArCot & Fox
pArdo etal.sumrAll &
broChuWAgner
  




      
        

        
ziegler

        
     
       

        

 



  
shigetA
  Gaudryceras     

       
 
    
     
goebbels
    






        
Gaudryceras



         
  


     
     


Gaudryceras


         
        

       
        
     
 
  

      Gaudryceras      
     



 

Wedekind
 
kullmAnn
& WiedmAnn      

     
mAtsumoto       



          


        
         



    
     

        




Cuvier
Zittel
Arkell

HyAtt
NeumAyr
      
       
     

     
   

 
  


       
        
       

sChindeWolF,
     
     

         

  


 
      

         
 

        
 sChindeWolF     
  
      Lytoceras
       
Tetragonites engeser & keupp  
   riegrAF & luterbACher 
 nemoto & tAnAbe     
     
   

       


      
     
         
doguzhAevAtAnAbe
etal.,


       
        
      Lytoceras
secernendumde steFAni
 Lytoceras  
   Eolytoceras Analytoceras
     

    
     
      
sChindeWolF
     uhlig    
       
       

      
    

      
    Lobolytoceras siemensi
keuppriegrAF etal.,
 Derolytoceras Trachylytoceras  
      
 Lytoceras CAllomon  meister 
 
rulleAu      Zelandites 
 Anagaudryceras
Anagaudryceras


      

NeumAyr
hyAtt,spAth,
spAth
spAth
SpAtH
       
     

       
       

   

       

EctocentritesCANAvAri
CosmolytocerasspAth    
EctocentritescanavariibonArelli

AmmonitespetersihAuer
bonArelli

       
     


        
       
        
        
        







       




Wähner 
hillebrAndt

Wähner
      


          
          
          


        
      

  
       
hAuerWähnersChindeWolF

Ectocentritespetersi


     Lytotropites
LytoconitesFucinitesBaltzerites
       
    sChindeWolF 
      
Eolytoceras
    WiedmAnn 
  Ectocentrites 
sChindeWolF  
  
 
WiedenmAyer
Arkelletal.
EctocentritesLytotropites
Lytotropites
         
  Holcolytoceras  Ectocentrites  
Arkell et al.,       
EctocentritesHolcolytoceras
  
         

Holcolytoceras

Holcolytoceras     Wähner
  
       
  hAuers  Ammonites petersi 
     Arkell et al. 
      meister
et al.,   Ectocentrites    
 

Ectocentriteshillebrandti
blAu etal.,
Ectocentrites       


Ectocentriteshillebrandti
Ectocentrites    
raricostatum
      
     hAuer 
WähnerbonArelli krumbeCk
géCzypálFy etal.,kment,
dommerguesmeister etal.,géCzy &
meisterhoFFmAnn & keuppmeister
et al.,       
      
  meister & Friebe   
 Ectocentrites    


 EctocentritescanavariibonArellibonArelliEctocentrites
petersihAuerhAuer
EctocentritespetersiWähner
Ectocentritespetersi
WiedmAnn
 
HolcolytocerasSpAtH

 Ammonites nodostrictusQuenstedt
spAth

      
        
       

      
      

       
      
   
       
      
       
 

        




         
  
WiedmAnn 

        
Holcolytocerasnodostrictum
       
WiedmAnn      
  Quenstedt    keupp & ilg

         
 

Holcolytoceras WiedmAnn
keupp WiedmAnn   
      Holcolytoceras
EctocentritesHolcolytoceras
  spAth     
 neumAyr   venturi
& nAnnArone     
 WiedmAnns
    Holcolytoceras
 Aegolytoceras     
Aegolytoceras     
 Audaxlytoceras    venturi &
nAnnArone
 Holcolytoceras  Aegolytoceras 
   WiedmAnn   
        
  Aegolytoceras     
    Holcolytoceras  
  Aegolytoceras    
       
Aegolytoceras      
Holcolytoceras       
WiedmAnn
Holcolytoceras
       
 ibex    
Arkell etal.,
 AdnethicerasWiedmANN
 Ammonites adnethicushAuer  
        WiedmAnn

       

        
       
      
         
 HolcolytocerasnodostrictumWiedmAnn
 Ammonitesnodostrictus Quenstedt   Holcolytocerasnodostrictus
WiedmAnn
 
       
       
         
      
       
      
     
 Tragolytoceras      

   


 AmmonitesadnethicushAuerAdnethicerasWiedmAnn
    Adnethiceras
WiedmAnn      Adnethicerasadnethicus    
hAuerAdnethiceras
adnethicumsAlFeld
 






       
    


        
hAuersAlFeldWiedmAnn
Adnethiceras
       
WiedmAnnAdnethiceras
      
rAkús
        
      Ectocentrites
 Adnethiceras       
Adnethiceras

WiedmAnn
 PeltolytocerasSpAtH
EctocentritesgiordaniibonArelli, 
spAth

      

       
         
      
         
        
      

 
venturi & bilottA 

       
      

       
     




         
        
      

WiedmAnnventuri
& bilottA
Peltolytoceras
     
Peltolytoceras       
       
WiedmAnn   venturi & bilottA 
Peltolytoceras     
spAthArkell etal.rAkús
WiedmAnn        

AnalytocerasEolytoceras
     
  venturi & bilottA  
ExomilocerasWiedenmAyer  Galaticeras
  Peltolytocerasgiordanii
WiedmAnn  Peltolytocerasgiordanii 
bonArelliPeltolytocerasWiedmAnn
 
spAthPeltolytocerasspAth
      
     

    
    
 venturi & bilottA  venturi
& nAnnAroneventuri & nAnnArone

rAkús      
     
CastanyicerasrAkús & guex 
 spAth  venturi et al., 
     Exomiloceras  
       
    Peltolytoceras 
  
Exomiloceras
 Castanyiceras     
        
     
     
longridge & smith

WiedmAnn
GalaticerasSpAtH
 Amphiceras harpoceratoidesgem
mellAro
spAth
   

       
        
    
      
  




       
   
         
       

        
      
        
       
 


      

      
venturi & bilottA
     venturi & bilottA
venturi, nAnnArone & bilottA
       Galaticeras
harpoceroides
Galaticeras 
rAkús & guex 
  venturi & bilottA   
     
     
zittelArkelletal.hoWArth
 Galaticerasharpoceroides
gemmellAro
 
& donovAn  dommergues et al.  el
hAriri et al.    bremer
 WiedmAnn  WiedenmAyer 
  guex & rAkús
rAkús   Galaticeras   
   
   Bouhamidoceras    
sArih etal. 
venturi & bilottA
venturi, nAnnArone & bilottA
Galaticeras 
Bouhamidoceras


Galaticeras 
WiedenmAyerventuri

      
     
 
Arkell etal.,
venturi etal.,sArih etal.,
HyAtt
       
        
buCher & guex,
       
  

 PleuroacanthitesCANAvAri
Pleuracanthiteszittel    
ParapsilocerashyAtt, 
PsilocerasPsilocerascalliphyllumpolycyclumWähner

 Ammonites biformissoWerby In:de
lA beChe         Lytoceras
biformesoW  CAnAvAri
 

      
      
     
Wähner    

   
       
    
       
       
      
       
       





        
  
        
       
        


        

        


 
            

         
        

       
        

     CAnAvAri  
WähnerWiedmAnn
Pleuroacanthites
      CAnAvAri
 PleuroacanthitesAmmonites
biformissoWerby  Lytoceras  biforme 
CAnAvAri    CAnAvAri  
  Pleuracanthites    
 WähnerlAnge
Pleuracanthiteszittel
        Lytoceras articulatum
soWerby      
Analytoceras      
        
Arkell hoWArth
Pleuroacanthites
       
Psilocerasguex
Wähner
  Pleuroacanthites  Psiloceras
guex
guex etal.    
    Psiloceras 
EuphyllitesPleuroacanthitesdommergues
& CAttAneo  tAylor  
   Pleuroacanthites  Alsatites
Proarietites

 
      
      
Arkell et
al.,guex,pálFyhAll, pitAru &
hendersonyin etal.,
 EolytocerasFrebold
EolytocerastasekoiFrebold
    Frebold

       
        
     

       
      
        
  


         
       
      
  Pleuroacanthites biformis              
WähnerPleuroacanthitesbiformis
       Wähner
PleuroacanthitesbiformisWähner
PleuroacanthitesbiformisArkell etal.
CAnAvAriPleuroacanthitesbiformis

WiedmAnnCAnAvAri
 
 
WiedmAnn
          
     

 WiedmAnn
  rAkús     

       
      longridge et
al.,  tAylor   hillebrAndt 

          
   
longridge etal.,
       
        
       

 
        
Frebold,WiedmAnn
 Eolytoceras tasekoi 


     tAylor
 hillebrAndt        
Eolytoceraschongi
  Eolytoceras     
 WiedmAnn
 Eolytoceras     
    sChindeWolF 
   rAkús     
Eolytoceras 

    Eolytoceras tasekoi
Ectocentritesguex
longridge etal.,

Eolytoceras    
      
    
Frebolddommergues kment 
hillebrAndt  tAylor   
     longridge et al.,

 AnalytocerasHyAtt
TrachyphyllitesArthAber    
 Trachyphyllites costatusArthAber    

LytocerasarticulatumWähner

hyAtteAstmAnn
 
   Eolytoceras  EolytoceraschongihillebrAndt,  

hillebrAndt
 
       


        
   
      
      

  




        




 

      
        
      
       
         
        
Lytoceras



     
 
      

         
        
Wähner  Wähner
       
          
  
        
      
CAnAvArisAlFeld
Analytoceras
      hyAtt
  Lyt
articulatumWähner Arkell et al.
Ammonites articulatussoWerby  de lA beChe
         
WähnersLytocerasarticulatum
  CAnAvAri    
    soWerby Ammonites
articulatum  de lA beChe   
 d’orbignys      


      hyAtt 
        
WähnerArkell etal.
       Analytoceras
articulatum
      
Analytoceras  
Lytoceras  WiedmAnn   
Trachyphyllitescostatus
 sAlFeld  




        
   Lytoceras Lytoceras mbriatum 
   Wähner    

     Analytoceras
 Lytoceras        
   Trachyphyllites costatus 
  AnalytocerasWähner   
   Analytoceras articulatum
   Ammonites hermannigümbel 
  Wähner,       
 Analytoceras articulatum    
 
        
Trachyphyllitescostatus

    WiedmAnn   
ArthAbers
    Analytoceras   
       
   Trachyphyllites  
venturi & bilottA
gümbel
   Ammonites hermanni   
Trachyphyllites costatusArthAber,   
Analytocerashermannigümbel
       
      
    Trachyphyllites  
      Arkell et al.,
luppov & drushChits  
bAssesChindeWolF
  Trachyphyllites    
      
ArthAber WiedmAnn
 WiedmAnn
        
       
    
       
Trachyphyllites
    houšA    
teiChertshevyrev
 
 Analytoceras hermannigümbel    Wähner    

WähnerAnalytocerashermannigümbel
  Wähner   Analytoceras
hermanni
veitkeuppTrachyphyllitescostatus
bAsseAnalytocerashermanni
TrachyphyllitescostatusAnalytocerasarticulatum
WiedmAnn Analytocerasarticulatum 
Analytocerasarticulatum

Trachyphyllites
 
sChindeWolF     
   
tozer
     
ArthAber       
Trachyphyllites

 WiedmAnn       
krystyn
Trachyphyllitescostatum
    Ectocentrites 
krystyn
       
Audaxlytoceras 

WiedmAnn
  
  
hoFFmAnn & keuppkrumbeCk
   Analytoceras    

 
 krumbeCks     
Pleuroacanthites Analytoceras canavarii 
 venturi & nAnnArone     


 Analytoceras   
     Analytoceras canavarii
    Tragolytoceras 
       
     

Analytoceras     

CAnAvAriWähner
krumbeCk ArthAberkrystyn
dommerguesbertinelli etal.,
NeumAyr
       
        

buCher
et al.,       


 
        


 Analytoceras
AnalytocerashermanniTrachyphyllitescostatumAnalytocerasarticulatum

 
 LytocerasSueSS
AmmonoceratitesboWdiCh  Ophiceras
suess    griesbACh   Arkell
et al.,  ThysanocerashyAtt   
Ammonites cornucopiad’orbigny     
   young & bird   Thysanoceras
orbignyibuCkmAn      
buCkmAnThysanolytocerasbuCkmAn
Ammoniteseudesianusd’orbigny   
   FimbrilytocerasbuCkmAn 
AmmonitesmbriatussoWerby 
KallilytocerasbuCkmAn 
  Kallilytoceras interlineatumbuCkmAn 
    CrenilytocerasbuCkmAn
CrenilytocerascrenatumbuCkmAn
    OrcholytocerasbuCkmAn
   Lytoceras cornucopiaethompson 
young & bird    Eulytoceras
spAth  HemilytocerasspAth  Metalytoceras
spAth  PterolytocerasspAth  Saturnoceras
Anderson  BiasalocerasdrushChits  
BiasalocerassubsequensdrushChits 
Valentolytocerasbesnossov
Valentolytoceras elegansbesnossov     
besnossov    Dinolytoceras
besnossov     Dinolytoceras zhivagoi
besnossovbesnossov

Derolytocerasrosenberg,
AmmoniteslineatustortusQuenstedt
spAth
romAnArkell et
al.,TrachylytocerasbuCkmAn
Ammonitesnitidusyoung & bird
buCkmAn

AmmonitesmbriatussoWerby
     

      
  stevens 
      
         
       
  
