Alexander Nützel

• Research Curator at Bayerische Staatssammlung für Paläontologie und Geologie

Cowries, the family Cypraeidae, form a diverse and conspicuous group of gastropods living in tropical to subtropical seas. Their shell is convolute (last whorl covers all previous ones) with a narrow, slit-like siphonate aperture bearing denticles (“teeth”). When extended, a large part of their shell surface is covered by a soft fleshy mantle. The...

Orthoceratoid cephalopods are common in the Palaeozoic rock record but became extinct in the Late Triassic. Many orthoceratoids contain cameral deposits, which are enigmatic calcareous structures within their chambered shell that presumably balanced their straight conchs in a horizontal position. Since the mid-19th century, palaeontologists have at...

Notwithstanding considerable efforts and new data on gastropod evolution collected in the recent decades, the origin of Neogastropoda remains still elusive. In this contribution we compare and ­discuss members of three extinct families previously proposed as possible neogastropod stem groups, i.e., Maturifusidae Gründel, 2001, Pseudotritoniidae Gol...

A new collection of Upper Jurassic (Kimmeridgian) gastropods from the reefal limestones of the Saal quarry near Kelheim (Lower Bavaria, Germany) is reported. It has yielded 119 species of which 80 species are nominate species, the others are treated in open nomenclature. This increases the number of known gastropod species from the Saal quarry by 5...

A new collection of Upper Jurassic (Kimmeridgian) gastropods from the reefal limestones of the Saal quarry near Kelheim (Lower Bavaria, Germany) is reported. It has yielded 119 species of which 80 species are nominate species, the others are treated in open nomenclature. This increases the number of known gastropod species from the Saal quarry by 5...

Evolutionary relationships of fossil gastropods have largely been inferred using taxonomic systematics. Phylogenetic relationships between extinct gastropod groups and their relationship to extant groups are largely unresolved. Here we reconstruct the phylogeny of Pleurotomariida, which has the longest fossil record among extant gastropod clades an...

Cameral deposits are enigmatic calcareous structures within the chambers of orthoceratoid cepha-lopods that were thought to be part of the living animal as far back as the mid-19th century. While the function of the deposits has been attributed to counterbalancing the straight cephalopod shells into a horizontal position, their formation cycle has...

The upper Carnian Heiligkreuz Formation (Dolomites, N Italy) overlies the Ladinian/Carnian Cassian Formation. At its type locality, the Heiligkreuz Formation seems to represent a marginal marine/coastal swamp deposit. However, the Heiligkreuz Formation also comprises basinal deposits that are fully marine and hardly distinguishable from the Cassian...

Natural history museums house numerous previously undescribed species and unknown information hidden in their collections. We describe lower Carboniferous slit-bearing gastropods (order Pleurotomariida, subclass Vetigastropoda; and family Goniasmatidae, subclass Caenogastropoda) from previously unreported gastropod collections made by Jane Longstaf...

Rinaldo Zardini (1902–1988) was an Italian palaeontologist and botanist born in Cortina d’Ampezzo. Having a background as a professional photographer, he was able to illustrate his collection of mostly tiny fossils in high definition. For his significant contributions to the field of palaeontology he received an honorary degree from the University...

The platycerate gastropods Orthonychia yutaroi Ebbestad, sp. nov. (Ordovician, Boda Limestone, Sweden), O. enorme (Silurian, Sweden, Gotland), O. parva (Pennsylvanian, Finis Shale Member, USA), and Orthonychia sp. (Mississippian, Imo Formation, USA) are studied including their protoconch morphology. Orthonychia yutaroi is the oldest known species i...

Pleurotomariida has the longest fossil record among extant gastropod groups, which extends back to the Cambrian–Ordovician. Pleurotomariida is a major clade in gastropod evolutionary history, comprising around 25–30 % of late Palaeozoic global gastropod generic diversity. Diversity of Pleurotomariida dropped significantly at the end-Permian mass ex...

High-spired Murchisonia-like slit-band gastropods are an important component of late Paleozoic gastropod faunas. Twenty-seven genera of such gastropods have been reported from the Permian, most of which representing the caenogastropod family Goniasmatidae. Only four genera, Trypanocochlea, Wannerispira, Laschmaspira, and Altadema crossed the Permia...

The early Mesozoic witnessed evolution of novel bivalve groups and innovation of diverse ecologic strategies. Although some newly evolved groups disappeared (e.g., Harpax), some persist until today (e.g., Cuspidariidae, Thyasiridae). Harpax (Norian-early Toarcian) is a globally widespread genus and a secondary soft substrate recliner, cemented to s...

Benefiting from their adaptability to extreme environments, subsurface microorganisms have been discovered in sedimentary and igneous rock environments on Earth and have been advocated as candidates in the search for extraterrestrial life. In this article, we study iron-mineralized microstructures in calcite-filled veins within basaltic pillows of...

Tropische Riffe gehören zu den vielfältigsten Ökosystemen der Erde. Die größte Diversität bzw. Artenzahl steckt allerdings weniger in den riffbildenden Organismen (z. B. Korallen, Schwämme) als in den riffbewohnenden Tieren und Pflanzen. Viele fossile Riffe hohen geologischen Alters sind massiv versteinert (lithifiziert) und ihre Ablagerungen stark...

During the transition from the Paleozoic to the Mesozoic, marine communities went through major changes in clade composition and proportions. A significant shift happened in the proportion between the Paleozoic Evolutionary Fauna and the Modern Evolutionary Fauna. The Permian-Triassic transition also marks the establishment of molluscs as the most...

The paleontological collection of Georg Gasser gives important insights in the fossiliferous sites of the 19th and 20th century, and the fossils collected and studied during that time interval. With about 90% the invertebrates represent the biggest part of the paleozoological specimens. All major groups are represented, although there is a clear pr...

Forty gastropod species of the subclass Heterobranchia are described from the Upper Jurassic (Upper Kimmeridgian) reefal limestones of South Germany, including ten species in open nomenclature and further ten species of uncertain identity. Six species are new to science: Ceritella convexa sp. nov., Nerinea donosa sp. nov., Endoplocus acutus sp. nov...

Forty gastropod species of the subclass Heterobranchia are described from the Upper Jurassic (Upper Kimmeridgian) reefal limestones of South Germany, including ten species in open nomenclature and further ten species of uncertain identity. Six species are new to science: Ceritella convexa sp. nov. , Nerinea donosa sp. nov. , Endoplocus acutus sp. n...

A reef-associated mollusc fauna (gastropods and bivalves) and its facies context are described from latest Triassic (Sevatian–Rhaetian) reef carbonates of Austria (Rötelwand reef at Gaissau and Gosaukamm near Hallstatt). The studied carbonates from the Rötelwand reef consist of mollusc-rich rudstones, partly boundstones, which contain branched cora...

The Upper Triassic Khao Nam Yot Formation (Carnian–Norian) of Wichian Buri District, Phetchabun Province, Northeastern Thailand contains mainly conglomerate interbedded with sandstone. The conglomerate is poorly sorted and consists mainly of limestone pebbles which are up to 1 m large and of sandstone, siltstone and mudstone pebbles. The matrix of...

The early Mesozoic experienced some of the biggest biotic crises of the Phanerozoic coupling with major climate perturbations. Following the Middle Triassic recovery period from the end-Permian mass extinction, two mass extinction events occurred, one during the Carnian (Late Triassic) and one at the end-Triassic. Previous analysis by Dal Corso et...

The late Triassic Cassian Formation, situated in the Dolomites (Southern Alps, North Italy), is outstanding because of its high marine invertebrate biodiversity and excellent preservation. Several fossil Cassian assemblages were studied regarding their diversity and palaeoecology. The assemblages are mostly ecologically very different to each other...

Neritimorpha is the smallest extant subclass of the class Gastropoda. Most of its members are marine but it also includes species in freshwater and on land. Its oldest members have possibly an Ordovician age. Although their diversity and abundance is low in comparison with that of the other gastropod clades, they are continuously present throughout...

Neritimorpha is the smallest extant subclass of the class Gastropoda. Most of its members are marine but it also includes species in freshwater and on land. Its oldest members have possibly an Ordovician age. Although their diversity and abundance is low in comparison with that of the other gastropod clades, they are continuously present throughout...

A new seguenziid gastropod, Varicoturbo microstriatus n. gen. n. sp., is described from the Upper Triassic (lower Carnian) St. Cassian Formation (Dolomites, Italy). This species is remarkable because it is the first known Triassic gastropod that has multiple distinct shell varices, a morphological feature that becomes common from the Cretaceous onw...

Gastropoda experienced many major shifts in its evolutionary history including extinction of most of the early groups, survival of a few, and radiation of novel groups. Pleurotomariida (slit shells) is one of the most ancient gastropod groups and has the longest fossil record among living gastropods. It can be traced back to the Cambrian–Ordovician...

Gastropoda suffered a great deal of extinction at the end-Permian. Although the magnitude of extinction was not as devastating as in other invertebrates, this event was a game changer for the evolution of the class Gastropoda and its consequences are effective until today. New gastropod faunas including yet undescribed ones from Oman, Pakistan, Tim...

Purpurinidae is an extinct gastropod family, which is considered a possible sister or stem group of neogastropods. The earliest confirmed members of the family are known from the Upper Triassic of the St Cassian Formation (Dolomites, Italy) while the latest became extinct before the end of the Early Cretaceous. Nearly 30 genera were assigned to the...

Permian gastropods from Thailand have been extensively studied over the last few years. The earliest known fossil collection was recovered in 1967 but has never been figured or described. Here, we document this historically important gastropod assemblage excavated from the upper-Lower to Middle Permian Ratburi Group of Khao Mang Lat in the Ban Kao...

Pleurotomariida have the longest fossil record among living gastropods and are diverse and abundant in the middle and upper Palaeozoic. Its traditional classification is based on adult shell characters. The early shell morphology has been largely unknown. We describe exceptionally well‐preserved Pleurotomariida from the Pennsylvanian marine shales...

The St. Cassian Formation, Italy, has yielded the most diverse marine invertebrate fauna known from the Triassic. A quarter of all described Triassic gastropod species has been reported from this formation. Most of the gastropod species from the St. Cassian Formation were erected in the 19th century and many of them are known only from their origin...

Protandrous sex change (sex change from male to female) is one of the diverse sexual expressions exhibited by bivalves, but its expression in the shell is quite rare. Previous studies on living and fossil astartids suggest a relationship between protandrous sex change and the formation of crenulations on the ventral shell margin at later ontogeneti...

Parasitism and similar life styles such as carnivorous grazing or mucus feeding without killing the prey are important in marine gastropods. Some of the most diverse living gastropod families have this feeding behavior. Taxonomic uniformitarianism is the most important tool to infer parasitism or similar life styles in fossil gastropods. The extant...

Middle Permian marine invertebrate assemblages from Central Thailand are strongly dominated by gastropods. Two gastropod assemblages from the Tak Fa Limestone at Khao Noi and Khao Chao Thong of the Nakhon Sawan area are the first Permian ones from Thailand that are analysed regarding diversity and composition based on quantitative data. Both gastro...

Taphonomic effects complicate the assessment of variations in biodiversity over time. Most pre-Cenozoic fossil assemblages have been altered through taphonomic effects, such as lithification and aragonite dissolution. Several studies have found alpha (local) and gamma (global) diversity in marine ecosystems to be low in the early Mesozoic and then...

Two marine invertebrate fossil assemblages from the Late Triassic Cassian Formation (Dolomites, northern Italy) were examined to assess their diversity and palaeoecology. Surface and bulk samples from the localities Misurina Landslide and Lago Antorno were taken and analysed separately. Both benthic assemblages are relatively similar in taxonomic c...

A monospecific mass occurrence of the new gastropod species Freboldia carinii sp. nov. is described from the Middle Triassic Esino Limestone of the Brembana Valley, Southern Alps, Italy. It is the second species assigned to the genus Freboldia that was initially described from the Early Jurassic of Ellesmere Island, Canadian Arctic. This gastropod...

Drill holes provide valuable information about palaeoecological interactions in fossil ecosystems, but the Jurassic drill‐hole record is scarce. We report circular drill holes in the infaunal bivalve Eothyasira antiqua (Münster in Goldfuss) from the Pliensbachian grey shales of the Amaltheenton Formation of Franconia, southern Germany. The outcrop...

The Society of Vertebrate Paleontology (SVP) has recently circulated a letter, dated 21st April, 2020, to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). In this letter, significant changes to the common practices in palaeontology are requested. In our pr...

The Society of Vertebrate Paleontology (SVP) has recently circulated a letter, dated 21st April, 2020, to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). In this letter, significant changes to the common practices in palaeontology are requested. In our pr...

Recently, the Society of Vertebrate Paleontology (SVP) has sent around a letter, dated 21st April, 2020 to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). The signatories of this letter request significant changes to the common practices in palaeontology....

The plicatulid bivalve Harpax spinosus is a common element of Pliensbachian to Lower Toarcian benthic community relicts occurring preferredly in fine-grained siliciclastic and mixed carbonate-siliciclastic sediments. There is general agreement that the bivalve was a secondary soft substrate dweller, being cemented with its flat to slightly concave...

The Early Permian (Kungurian) Khao Khad Formation of Central Thailand consists mostly of carbonates deposited on the western margin of the Indochina Terrane. This formation has yielded unusual microbial-fusulinid limestones with large gastropods which contribute most to the rock volume. With a height of more than 6 cm, the gastropods are amongst th...

The dark clays of the Lower Jurassic (Upper Pliensbachian) Amaltheenton Formation in Buttenheim, Franconia yield a diverse and well-preserved benthic and nektonic macrofauna, dominated by bivalves, gastropods, and ammonites. In the present study the bivalve fauna is described based on new collections of ca. 7000 specimens. A comprehensive taxonomic...

Beta diversity, the compositional variation among communities, is often associated with environmental gradients. Other drivers of beta diversity include stochastic processes, priority effects, predation, or competitive exclusion. Temporal turnover may also explain differences in faunal composition between fossil assemblages. To assess the drivers o...

A new Permian gastropod assemblage from the Roadian (Middle Permian) Khao Khad Formation, Saraburi Group (Lopburi Province, Central Thailand) which is part of the Indochina Terrane, has yielded one of the most diverse Permian gastropod faunas known from Thailand. A total of 44 gastropod species belonging to 30 genera are described herein, including...

Order Pleurotomariida is one of the most diverse gastropod groups of Late Paleozoic seas. The diversity of Pleurotomariids had its acme in the Carboniferous and decreased continuously afterwards. Understanding the life history traits might help to better understand the intrinsic factors that might have played a role in their extinction. We analysed...

Mainland Southeast Asia was formed by the collision of two main terranes, the Indochina terrane in the East and the Sibumasu terrane in the West, during latest Paleozoic to early Mezosoic times. Two Middle Permian gastropod assemblages from two localities in Central Thailand, which were collected from the Tak Fa Limestone of the Indochina terrane a...

The Middle Permian of Central Thailand has long been part of intensive research focusing on stra-tigraphy, sedimentology and tectonic evolution. It is characterised by complex reef-bearing carbonate platform and basin development (Pennsylvanian to Guadalupian) prior to the Indosinian orogeny (Lower-Middle Triassic) resulting in complex tectonic pat...

Myriotrochids are small, infaunal apodid sea cucumbers that occur in bathyal, abyssal and hadal depths of modern seas but have been also found in artic and sub-arctic shallow waters. The presence of myriotrochids, stem-group myriotrochids and apodid relatives in the fossil record is mostly indicated by isolated distinctive body-wall ossicles and ca...

With 1429 animal species, the Triassic Cassian Formation in the Dolomites, Southern Alps (Italy), yields the highest species richness reported from any spatially constrained pre-Quaternary formation known to science. The high preserved diversity is partly attributable to a high primary diversity governed by the tropical setting, increasing alpha di...

A new silicified Middle Permian gastropod fauna is reported from Central Thailand. It is the first diverse Permian gastropod assemblage described from the Sibumasu terrane. The gastropod fauna comes from fore-reef shallow water carbonates of the Middle Permian (Wordian) limestones of the Ratburi Group exposed at Khao Phrik, Ratchaburi Province. Thi...

Many conservation lagerstätten feature excellent fossil preservation, but the environmental conditions responsible for the preservation, such as anoxia or hypersalinity, are often not favorable for highly diverse communities. Concentration lagerstätten contain abundant fossils that are commonly not well preserved, which inhibits taxon identificatio...

The mid-Pennsylvanian (Desmoinesian–Virgilian) deposits from the Buckhorn Asphalt Quarry Lagerstätte near Sulphur, Oklahoma, are characterized by siliciclastic–carbonate rocks. One of these deposits is the ‘cephalopod coquina’ that contains a large amount of orthocerid and coiled nautiloid, and ammonoid shell remains. These were used for a detailed...

Geology, palaeontolgy and diversity of the Late Triassic Cassian Formation, Dolomites, N Italy

Comparing diversity among different ecosystems is difficult even in modern environments, but the biases in the fossil record yield many more challenges. Variations in sampling intensity and preservation over time and space are the major problems. Variability of fossil preservation is usually countered with subsampling, which in essence degrades wel...

A new early middle Anisian (Bithynian) gastropod fauna is described from the Mahmudia quarry in North Dobrogea, Romania. At least 22 species are reported, nearly all of them from Tubiphytes‐limestones which represent a microbial buildup. Twenty species from Tubiphytes‐buildup limestones are characterized, ten of which in open nomenclature due to in...

A new record of halimedacean algae is reported from the Upper Triassic (Carnian) of the Dolomites (Southern Alps) near Cortina d'Ampezzo. Based on the gross morphology (non-segmented non-branched thalli) and the internal skeletal arrangement (e.g., medulla with thicker siphons, sometimes bifurcating at high angles; cortex with thinner siphons with...

...The shells derive from the ‘cephalopod coquina’ that represents the deepest-water deposit within the single cycle of trans- and regression in the outcrop. ...The shells were cast and investigated with a scanning electron microscope...The ichnotaxon associations in the shells indicate different modes of deposition...

Cephalopod remains from the Desmoinesian (Pennsylvanian, Upper Carboniferous) Buckhorn Asphalt Quarry (Oklahoma, USA) were studied intensively over the past decades. However, this is the first study that focusses exclusively on bioerosion affecting their shells. Research on bioerosion in these fossils was possible due to soaking of sediments and sh...

Thoughts on the Paleobiology Database - an essay in German

The Middle to Upper Triassic Cassian Formation (Dolomites, Northern Italy) is the most diverse early Mesozoic ecosystem worldwide. A compilation of taxa described from the Cassian Formation contains 1336 species after revision. The species richness is very high compared with other fossil lagerstätten known for their diversity. For example, 228 spec...

Composition and diversity of fossil assemblages from the Late Triassic Cassian Formation (northern Italy, Dolomites) are highly heterogeneous. Autochthonous basin and parautochthonous shallow water assemblages are present as well as shallow water assemblages transported into basinal settings during deposition. Ongoing bulk sampling and quantitative...

Ophiocistioids are small pentaradiate, free-moving globular echinoderms, related to sea urchins and sea cucumbers. Rare as fossils, and enigmatic in terms of their phylogenetic position, members of the Ophiocistioidea have been considered an exclusively Palaeozoic echinoderm group. Apart from articulated body fossils (Ordovician–Devonian), the foss...

A new Early Triassic marine fauna is described from an exotic block (olistolith) from the Ad Daffah conglomerate in eastern Oman (Batain), which provides new insights into the ecology and diversity during the early aftermath of the Permian–Triassic Boundary mass extinction. Based on conodont quantitative biochronology, we assign a middle Griesbachi...

Articulated ophiocistioids are rare as fossils, enigmatic in terms of their phylogenetic position, and have been considered to be an exclusively Palaeozoic echinoderm group. Apart from articulated body fossils, the fossil record of Ophiocistioidea is otherwise dependent on isolated microfossils. However, it has been demonstrated that disarticulated...

The Schlern and Seiser Alm area (South Tyrol, Italy) is a classical locality for studies of Middle Triassic platform to basin transitions, yet details of the palaeoecology of the rich benthic faunas of this area have been insufficiently known. We present herein a detailed palaeoecological study of the fauna from the Schlernplateau beds (Late Ladini...

Two fossil assemblages from the Late Triassic Cassian Formation (northern Italy, Dolomites) were investigated regarding palaeoecology and diversity. Both stem from landslide sites situated in the vicinity of Misurina and Lago Antorno. They consist of surface collections and bulk samples, which were washed and wet-sieved with a mesh size of around 0...

The Convention on Biological Diversity (CBD) commits its 196 nation parties to conserve biological diversity, use its components sustainably, and share fairly and equitably the benefits from the utilization of genetic resources. The last of these objectives was further codified in the Convention's Nagoya Protocol (NP), which came into effect in 201...

A single limestone sample from the Early Triassic (late Dienerian) of the Salt Range in Pakistan has yielded numerous small gastropods (smaller 2 mm), few bivalves and abundant ammonoids. The limestone is interpreted as a tempestite. Many of the gastropods are extremely well-preserved including protoconch preservation and micro-ornaments. Five spec...

The discovery of a preserved protoconch in the Late Triassic (Carnian) gastropod species Loxonema mersai from the Late Triassic St. Cassian Formation (N Italy) shows that this species has a larval shell displaying coaxial heterostrophy. This species does not represent the Palaeozoic genus Loxonema (with Silurian type species) but a new genus – Rach...

Owing to their great diversity and abundance, ammonites and belemnites represented key elements in Mesozoic food webs. Because of their extreme ontogenetic size increase by up to three orders of magnitude, their position in the food webs likely changed during ontogeny. Here, we reconstruct the number of eggs laid by large adult females of these cep...

2,604 names at the rank of subtribe, tribe, subfamily, family and superfamily have been proposed for Recent and fossil gastropods, and another 35 for monoplacophorans. All names are listed in a nomenclator giving full bibliographical reference, date of publication, typification, and their nomenclatural availability and validity under the Internatio...

In Franconia (S Germany), facies and depositional environment of claystones exposed in clay pits near Buttenheim/Kalchreuth and Mistelgau are similar to each other prior and after the Early Toarcian Posidonia-Shale event. They represent aerobic to dy-saerobics marine soft-bottoms in an almost identical palaeogeographical position. They yield benthi...

The rich benthic fauna of the Schlern and Seiser Alm area, which is one of the few places in the world where the platform-slope-to-basin transitional zone is preserved in its primary setting (Keim 2008; Brander et al. 2016), is known for more than 100 years but its palaeoecology has been insufficiently known. We present a detailed palaeoecological...

INTRODUCTION Deposits of the Pennsylvanian (Upper Carboniferous) Buckhorn Asphalt Quarry in southern Oklahoma, USA, are of mixed siliciclastic-carbonatic composition; however, crucial is the high content of hydrocarbons, that intruded the sediments during or only shortly after deposition. These hydrocarbons impregnated not only the deposits but mor...

A diverse assemblage of fishes (isolated teeth and scales) is reported from the Middle to Upper Pennsylvanian Buckhorn Asphalt Quarry Lagerstätte in Oklahoma, USA. The assemblage includes chondrichthyans such as the bransonelliform Bransonella lingulata, the xenacanthiform Xenacanthus, the symmoriiform Stethacanthus, ctenacanthiforms, an polyacrodo...

The Kimmeridgian and Tithonian Plattenkalk deposits of southern Germany (e.g., Solnhofen, Eichstätt, Pfalzpaint, Painten, Brunn, Wattendorf) are famous for their diverse and exceptionally preserved fauna and flora. So far, there are around 1,800 species reported from these strata. However, with the help of non-applied or hitherto unused micropalaeo...

A fossil invertebrate assemblage from the Late Triassic Cassian Formation (Dolomites, north Italy) has been investigated regarding biodiversity and palaeoecology. The bulk sample, consisting of several kilogramme sediment, was collected at a landslide site near Misurina. It was washed and sieved and the residue > 0.5 mm has been quantitatively pick...

The Middle Triassic (Ladinian) gastropod genus Trachybembix from the Marmolada Limestone in South Tyrol, Italy is reviewed based on the study of type material. Contrary to previous suggestions, Trachybembix has a selenizone and thus represents a member of the order Pleurotomariida. The genus is placed in the family Eotomariidae, an essentially Pala...