Article

The carinate bird Ichthyornis from the Upper Cretaceous of Mexico

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  • Museo de Paleontología de Múzquiz
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... The Piedritas site is an area of about 3 km 2 within the Ejido Piedritas, Ocampo Municipality, Coahuila State, northern Mexico, about 20 km south of the Mexico-USA border (Porras-Múzquiz et al., 2014). In this site located between 28°48'15.5" ...
... The fossil assemblage of this site includes well-preserved tests of planktonic foraminifers, and bivalves (including Inoceramus Sowerby, 1814, andPlatyceramus Heinz, 1932), gastropods, ammonites, crustaceans, marine reptiles (mosasaurs and pterosaurs), and Ichthyornis Marsh, 1872. The fishes recovered at this site include unidentified chondrichthyan teeth, remains attributable to Ichthyodectiformes, clupeomorphs, and those already identified as Enchodus Agassiz, 1835;Pachyrhizodus Dixon, 1850;andLaminospondylus transversus Springer, 1957 (Riquelme et al., 2013;Porras-Múzquiz et al., 2014). The lithologic sequence and fossil assemblage of Piedritas are similar to those reported at other nearby sites, previously reported as the 'Múzquiz Lagerstätte' of Coahuila, in which deposits belonging to the Eagle Ford and Austin groups are involved (Alvarado- Ortega and Porras-Múzquiz, 2009, Blanco-Piñón and Alvarado-Ortega, 2005, Giersch et al., 2008, Stinnesbeck et al., 2005, Riquelme et al., 2013. ...
... The lithologic sequence and fossil assemblage of Piedritas are similar to those reported at other nearby sites, previously reported as the 'Múzquiz Lagerstätte' of Coahuila, in which deposits belonging to the Eagle Ford and Austin groups are involved (Alvarado- Ortega and Porras-Múzquiz, 2009, Blanco-Piñón and Alvarado-Ortega, 2005, Giersch et al., 2008, Stinnesbeck et al., 2005, Riquelme et al., 2013. Although the fauna at Piedritas has yet to be studied thoroughly, Porras-Múzquiz et al. (2014) concluded that this is part of the Coniacian-Early Campanian deposits of the Austin Group. ...
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The discovery of the first Mexican fossil specimen belonging to the species Xiphactinus audax is reported here. This specimen was recovered in the Coniacian-Campanian marine deposits of the Austin Group at the Piedritas site, within the homonymous ejido, Municipality of Ocampo, north of Coahuila. Although the specimen is strongly fragmentary, partially preserved by impressions or molds of the bones, and only shows parts of the head, the opercular series, and the pectoral fins, this has enough anatomical features that allow its specific taxonomic determination. Among these diagnostic features, this fossil has a well-developed ethmopalatine bone, a well-developed supraoccipital crest, a maxilla anteriorly higher than the rest of the bone, and a very robust palatine articular head. Particularly, this fossil exhibits two distinctive features of the genus Xiphactinus, a row of conical teeth, irregularly sized and distributed in the maxilla and dentary bones, as well as a pectoral radius 1 extremely developed and at least 2.5 times wider than the subsequent ray. At the same time, its teeth are smooth and have no sharp edges or carenae, which allows its specific identification. The present discovery complements the geographical distribution of Xiphactinus confirming its wide longitudinal distribution throughout America.
... Remains of Ichthyornis, specifically, have been found from the Cenomanian to the Campanian (Clarke 2004). The best record of Ichthyornis specimens comes from the Smoky Hill Chalk Member of the Niobrara Formation in western Kansas (Martin and Stewart 1982), but the fossil taxon has been found as far no rth as central Saskatchewan and as far south as northern Mexico (Tokaryk et al. 1997;Porras-Múzquiz et al. 2014). ...
... Ichthyornis was a tern-sized seabird measuring about 24 cm long with a wingspan of approximately 43 cm (Gregory 1952;Olson 1985;Feduccia 1996;Shimada and Fernandes 2006;Porras-Múzquiz et al. 2014). This bird is well known for its toothed jaws, which were originally mistaken for lizard jaws (Marsh 1872), and later considered to be the jaws of small mosasaurs (Gregory 1952;Olson 1985). ...
... 50C). Observable diagnostic characteristics of the humeri of the genus include: large deltopectoral crest projected dorsally rather than anteriorly, apneumatic foramina, a long, narrow, and hollow shaft, robust distal portion, prominent dorsal supracondylar process, and a musculus pronator superficialis pit (e.g., Marsh 1880;Olson 1975;Parris and Echols 1992;Clarke 2004;Porras-Múzquiz et al. 2014). One inconsistent characteristic is the bowed shaft in FHSM VP-17478; the holotype has a relatively straight shaft (Olson 1975;Clarke 2004). ...
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We describe a previously unreported left humerus of the Late Cretaceous toothed seabird, cf. Ichthyornis sp., from the basal Lincoln Limestone Member (late Cenomanian) of the Greenhorn Limestone Formation in central Kansas. This specimen represents one of the oldest bird specimens in North America, and together with previously described ichthyornithid specimens, it also provides new insights into the size distribution of the fossil taxon. Our analysis indicates that Ichthyornis body size remained relatively consistent throughout its temporal range from the Cenomanian through the Campanian. The present fossil record suggests that Ichthyornis measured up to about 0.5 m in skeletal wingspan, 0.2 m in height, and 0.3 m in skeletal length.
... Up to now, the avian body fossil record for the Upper Cretaceous of Coahuila is only represented by the discovery of a disarticulated right humerus from Ichthyornis. This specimen was found at the Ejido Piedritas in strata corresponding to the Upper Cretaceous Austin Group of Coniacian-Campanian age (Porras-Múzquiz et al., 2014). Unfortunately, to date no tracks or trackways have been found that could be directly related to this Cretaceous bird, separated stratigraphically from the new web-footed bird tracks by at least 20 Ma; therefore a direct comparison with Leptoptilostipus isp, morphotype A and morphotype B is not possible. ...
Article
In this study we describe three new web-footed bird tracks found in uppermost Maastrichtian strata of Las Encinas Formation, southeast Coahuila, NE Mexico. The described materials were collected at Rancho San Francisco locality, Ramos Arizpe County. These bird tracks can be ecomorphologically compared with those of modern members of the Order Anseriformes and the Family Ardeidae (Order Pelecaniformes). Associated invertebrate ichnotaxa include Cochlichnus and Skolithos. The co-occurrence of Leptoptilostipus isp., morphotype A and morphotype B with several invertebrate traces at Rancho San Francisco suggests that this area could represent a feeding site with abundant food sources during the latest Maastrichtian. These new bird footprints add to the previous reports of avian trace fossils for the Upper Cretaceous of the state of Coahuila and suggest that the Rancho San Francisco tracksite can be considered up to now, as the richest locality of web-footed bird tracks worldwide.
... Finally, the Late Cretaceous ornithurine Ichthyornis dispar was included as outgroup of Neornithes [36]. The specimen I. dispar MUZ 689 was taken from [37]. ...
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From a functional standpoint, the humerus is a key element in the skeleton of vertebrates as it is the forelimb’s bone that connects with the pectoral girdle. In most birds, the humerus receives both the forces exerted by the main flight muscles and the aerodynamical stresses exerted upon the wing during locomotion. Despite this functional preeminence, broad scale studies of the morphological disparity of the humerus in the crown group of birds (Neornithes) are lacking. Here, we explore the variation in shape of the humeral outline in modern birds and its evolutionary relationship with size and the evolution of different functional regimes, including several flight strategies, wing propelled diving and complete loss of wing locomotory function. Our findings suggest that most neornithines evolved repeatedly towards a general humeral morphology linked with functional advantages related with more efficient flapping. Lineages evolving high-stress locomotion such as hyperaeriality (e.g., swifts), hovering (e.g., hummingbirds) and wing-propelled diving (e.g., penguins) greatly deviate from this general trend, each exploring different morphologies. Secondarily flightless birds deviate to a lesser degree from their parent clades in humeral morphology likely as a result of the release from constraints related with wing-based locomotion. Furthermore, these taxa show a different allometric trend that flighted birds. Our results reveal that the constraints of aerial and aquatic locomotion are main factors shaping the macroevolution of humeral morphology in modern birds.
... Hesperornithiforms vanish from the ecosystem in the transition to open ocean conditions (Fig. 2B) despite the presence of more fragile fossils of volant Ichthyornis in these deposits (e.g. Marsh 1880;Olson 1975;Porras-Múzquiz et al. 2014). Given this, the absence of hesperornithiforms cannot be interpreted as completely taphonomic, and the same factors limiting hesperornithiforms did not affect ichthyornithiforms. ...
... The early Late Cretaceous fossil record of ornithuromorph birds in North America is richer, but the pre-Campanian finds are all represented by Ichthyornis or morphologically similar forms (Tokaryk et al., 1997;Clarke, 2004;Shimada and Fernandes, 2006;Bell and Everhart, 2011;Porras-Múzquiz et al., 2014). The small tern-like avian taxon Ichthyornis, commonly considered as an ichthyophagous waterbird, has long been viewed as a classical example of evolution, mainly due to a combination of the supposedly advanced postcranial morphology and retention of the toothed jaws. ...
Article
Ornithuromorph birds (the clade which includes modern avian radiation) first appeared in the Early Cretaceous in Asia and achieved a great diversity during the latest ages of the Late Cretaceous (Campanian and Maastrichtian). The evolutionary history of orithuromorphs during the first 17 MYAs of the Late Cretaceous (Cenomanian to Santonian ages) remains very poorly known, as the fossil record for this time interval is largely restricted to several isolated finds of the classic avian genus Ichthyornis in North America. Here we describe an isolated distal tibiotarsus of an evolutionary advanced bird, morphologically similar to Ichthyornis, from the middle Cenomanian of Saratov Province, European Russia. This is the first documentation of an Ichthyornis-like bird in the Old World. The find further constitutes only the second pre-Campanian record of the Late Cretaceous Ornithuromorpha in Eurasia, the second record of Cenomanian birds in Russia. This discovery shows that Ichthyornis-like birds enjoyed a wide geographical distribution as early as the beginning of the Late Cretaceous. Given that the earliest and the most primitive ornithuromorph birds are known from Asia, the new find supports a Eurasian origin for Ichthyornithidae.
... Together with crown birds, the Ichthyornithiformes and the Hesperornithiformes form the Ornithurae (ornithurine birds). Representatives of these crownward stem ornithurines are known from the Late Cretaceous (c. 100 to 66 Ma) of northern and central America -for the Ichthyornithiformes-and the Holarctic region -for the Hesperornithiformes (e.g., [4,6,[8][9][10][11]). None of the toothed bird lineages survived the 66 Ma extinction crisis [4]. ...
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Background The dentitions of extinct organisms can provide pivotal information regarding their phylogenetic position, as well as paleobiology, diet, development, and growth. Extant birds are edentulous (toothless), but their closest relatives among stem birds, the Cretaceous Hesperornithiformes and Ichthyornithiformes, retained teeth. Despite their significant phylogenetic position immediately outside the avian crown group, the dentitions of these taxa have never been studied in detail. To obtain new insight into the biology of these ‘last’ toothed birds, we use cutting-edge visualisation techniques to describe their dentitions at unprecedented levels of detail, in particular propagation phase contrast x-ray synchrotron microtomography at high-resolution. Results Among other characteristics of tooth shape, growth, attachment, implantation, replacement, and dental tissue microstructures, revealed by these analyses, we find that tooth morphology and ornamentation differ greatly between the Hesperornithiformes and Ichthyornithiformes. We also highlight the first Old World, and youngest record of the major Mesozoic clade Ichthyornithiformes. Both taxa exhibit extremely thin and simple enamel. The extension rate of Hesperornis tooth dentine appears relatively high compared to non-avian dinosaurs. Root attachment is found for the first time to be fully thecodont via gomphosis in both taxa, but in Hesperornis secondary evolution led to teeth implantation in a groove, at least locally without a periodontal ligament. Dental replacement is shown to be lingual via a resorption pit in the root, in both taxa. Conclusions Our results allow comparison with other archosaurs and also mammals, with implications regarding dental character evolution across amniotes. Some dental features of the ‘last’ toothed birds can be interpreted as functional adaptations related to diet and mode of predation, while others appear to be products of their peculiar phylogenetic heritage. The autapomorphic Hesperornis groove might have favoured firmer root attachment. These observations highlight complexity in the evolutionary history of tooth reduction in the avian lineage and also clarify alleged avian dental characteristics in the frame of a long-standing debate on bird origins. Finally, new hypotheses emerge that will possibly be tested by further analyses of avian teeth, for instance regarding dental replacement rates, or simplification and thinning of enamel throughout the course of early avian evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0753-6) contains supplementary material, which is available to authorized users.
... "Los Temporales" quarry is part of a group of interesting paleontological sites of Coahuila, which were recently discovered along the northern region of this Mexican State due to a significant increase in the extraction of flagstones for commercial purposes (e.g. Alvarado-Ortega & Porras-Múzquiz, 2009, 2012Gonz alez-Barba & Espinosa-Ch avez, 2005;Porras-Múzquiz, Chatterjee, & Lehman, 2014;Riquelme, Alvarado-Ortega, Ruvalcaba-Sil, & Aguilar-Franco, 2013;among others). Overall, the geology of this area is known for the exposition of large sequences of laminated calcareous shales, intercalated with argillaceous limestones and chalky strata, which often contain small and large pyrite crystals. ...
Article
Herreraichthys coahuilaensis gen. and sp. nov. is described based on a single specimen collected in the Santonian marls strata of the "Los Temporales" quarry, Coahuila State, northern Mexico. This new species shows the diagnostic characters of the Family Lepisosteidae and tribe Lepisosteini, together with Lepisosteus and Atractosteus. This new fish shows two rows of teeth on dentary and lacrimomaxillae bones, including a lingual row of sharp and small regular size teeth, as well as a medial row of longer and fang-like teeth; this also has a lacrimomaxillary series as the main bite element of the upper jaw and the plicidentine structure on teeth. This Mexican fish differs from the other lepisoestinis in two characters; its lacrimomaxillary series is composed of 32 bones that constitute the largest series as far known among lepisosteiformes, and its premaxilla is comparatively wider and shorter. The occurrence of this specimen into an open marine deposit with no freshwater elements suggests that Herreraichthys was a marine inhabitant; however, there is the possibility that this species was able to temporarily survive in the sea, as Atractosteus spatula does now.
... Early to Late Campanian -The Campanian deposits with dinosaur remains can be found in abundant localities in the north of Mexico. These deposits make up the El Gallo Formation of El Rosario and Eréndira (Langstone and Oakes, 1954;Morris, 1967Morris, , 1976Hernández-Rivera et al., 1997;Rodriguez-de la Rosa and Aranda-Manteca, 1999;Ford and Chure, 2001;Hilton, 2003;Johnson et al., 2006;Romo de Vivar, 2011;Peecook, et al., 2014), La Bocana Roja Formation of El Rosario (Molnar, 1974;Morris, 1981;Brodkorb, 1976;, Corral de Enmedio Formation, Camas Formation and Packard Formation of Naco-Cananea area (Taliaferro, 1933;Lull and Wright, 1942;Lucas et al., 1995;Lucas and González-León, 1996;Contreras-Medina, 1997;Duarte-Bigurra, 2013), San Carlos Formation of Aldama and Ojinaga (Westgate et al., 2002a(Westgate et al., , 2002bRivera-Sylva et al., 2011a), Pen Formation and Austin Group of Ocampo (Rivera-Sylva et al., 2011a;Porras-Múzquiz et al., 2014), Aguja Formation of Ojinaga, Manuel Benavides and Ocampo (Westgate et al., 2002b;Andrade-Ramos et al., 2002;Andrade-Ramos, 2003;Montellano-Ballesteros, 2003;Torres-Rodríguez, 2006;Rivera-Sylva et al., 2006a, 2008, 2009a, 2009b, 2011a, 2011cMonroy-Mújica, 2009;Torres-Rodríguez et al., 2010;Martínez-Díaz, 2011;Martínez-Díaz and Montellano-Ballesteros, 2011;Carpenter, 2014a, 2014b;Ramírez-Velasco et al., in press), San Miguel Formation of Saltillo (in this paper) and Cerro del Pueblo Formation of Ramos Arizpe, Saltillo, General Cepeda and Parras de la Fuente Hernández-Rivera et al., 1995;Hernández-Rivera, 1997;Rodríguez-de la Rosa and Cevallos-Ferriz, 1998;Hernández-Rivera and Delgado de Jesús, 1999;Kirkland et al., 2000;Eberth et al., 2003;Serrano-Brañas, 2006;Torres-Rodríguez, 2006;Rivera-Sylva and Espinoza-Chávez, 2006;Lund et al., 2007;Aguillón-Martínez, 2010;Loewen et al., 2010;Rivera-Sylva et al., 2011a, 2011bPrieto-Márquez and Serrano-Brañas, 2012;Aguilar et al., 2013Aguilar et al., , 2014Prieto-Márquez, 2013;Vivas-González, 2013;Rivera-Sylva and Carpenter, 2014a;Ramírez-Velasco et al., 2014). ...
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A specimen of the aquatic reptile Champsosaurus sp. from the Paleocene Black Peaks Formation in southwestern Texas is the southernmost yet known. The fragmentary specimen exhibits some unusual features, such as a great anterior extent of the quadratojugal on the lower temporal arch, and cannot be attributed with confidence to any of the named species. Champsosaurus appears to have been tolerant of temperate climates and had a northern latitudinal range exceeding that of crocodylians. It seems likely that the brief southward extension in range of Champsosaurus during early Paleocene time resulted from a decrease in mean annual temperature, comparable to over 10° of paleolatitude.
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Charles Darwin commented that Ichthyornis, as one of the “toothed birds” from the Late Cretaceous of Kansas, offered some of “the best support to the theory of evolution” (in litt., C. Darwin to O.C. Marsh, August 31, 1880). Ichthyornis figures no less prominently today. It is one of the closest outgroups to crown clade Aves, and remains one of the only Mesozoic avialans known from more than a handful of specimens. As such, Ichthyornis is an essential taxon for analyses of deep divergences within Aves because of its influence in determining the morphologies ancestral to the crown clade. Ichthyornis, however, has languished in need of new anatomical description and taxonomic revision. Many of the best Ichthyornis specimens were largely inaccessible, plastered into Yale Peabody Museum (YPM) exhibit mounts for nearly a century. The focus of this study was the entire YPM Ichthyornis collection, the largest at any institution. The elements removed from the mounts were identified to the specimens with which they were originally associated. Detailed morphological study of the 81 YPM specimens yielded the following results: (1) there is evidence for only one species of Ichthyornis, rather than the eight previously proposed; (2) 78 specimens are part of this species, Ichthyornis dispar; (3) two previously identified species are not part of Ichthyornis; and (4) one new species is identified. This analysis also provided a case study in the application of phylogenetic nomenclature at the species level. The morphology of Ichthyornis dispar is described in detail from the holotype and referred specimens. Phylogenetic analyses of 202 morphological characters, scored for 24 terminal taxa, evaluated the relationships among Mesozoic ornithurines including Ichthyornis dispar and the newly identified taxa. Analysis of 23 core taxa produced two most parsimonious trees (L: 384, CI: 0.66). Marsh's “Ichthyornithiformes” is not monophyletic: Two previously named species of Ichthyornis as well as Apatornis celer are placed as more closely related to or as part of Aves. The results of the phylogenetic analyses have implications for previous hypotheses of the timing and pattern of the origin of Aves.
Article
FHSM VP-2139 is the proximal end of a right carpometacarpus of the Late Cretaceous toothed seabird, Ichthyornis sp. (Aves: Ichthyornithiformes), housed in the Sternberg Museum of Natural History, Hays Kansas. The specimen was found near the contact between the Carlile and Greenhorn Formations in southern Ellis County, Kansas. The specimen marks the oldest record of Ichthyornis in Kansas, and this report represents the first detailed account of this specimen. The estimated total “skeletal length” (from the beak tip to the pygostyle tip) and “skeletal wingspan” (between the right and left phalangeal tips) of the bird individual are 24 cm and 43 cm, respectively. The bird specimen is paleoecologically intriguing, because it occurred in an offshore deposit which formed during the maximum transgressive phase of the Greenhorn Cyclothem of the Late Cretaceous Western Interior Sea.
Chapter
Three paleobiogeographic divisions characterized the Cretaceous Western Interior Seaway of N America during most of its history: a Cool Temperate N Interior Subprovince; a Mild Temperate Central Interior Subprovince; and a Warm Temperate S Interior Subprovince. To the S lay the Subtropical Gulf and Atlantic Coast Subprovince, and the Tropical Caribbean Province. Stratigraphic data reveal 5 third-order eustatic cycles which inundated the interior of N America during the Cretaceous. In each, the distribution of paleobiogeographic units was dramatically altered within a 1-2Ma interval around peak transgression and eustatic highstand. These peaks were associated with abrupt paleoceanographic changes involving warming and amelioration of climates, normalization of salinity, and rapid fluctuations between well oxygenated waters and anoxic events. During these 1 to 2 Ma intervals, abrupt northward migration of Subtropical organisms as much as 1500 miles into west-central Canada, and of Tropical reef biotas into the southern United States, depict rapid northward incursions of Sub-tropical and Warm Temperate biogeographic units. These were followed rapidly by southward emigration to normal distributions. Major extinction events are commonly associated with these incursions, as are periods of rapid evolution among marine taxa. The major centers of endemism and the most rapid rates of evolution on North Cretaceous molluscs occurred within paleobiographic ecotones.-from Author
Article
Distribution patterns of marine vertebrates of the Cretaceous Western Interior Seaway of North America are analysed in a biogeographical context. The analysis is based on fossil vertebrate assemblages from the following Lower Campanian localities: (1) Anderson River fauna, N.W.T. (2) Pembina fauna, southern Manitoba (3) Sharon Springs fauna, South Dakota-Wyoming (4) Niobrara fauna, Kansas (5) Mooreville fauna, Alabama. Due to the cosmopolitan nature of many marine vertebrates, relative abundance is used in preference to presence-absence data in identifying faunal distribution patterns. The analysis demonstrates the presence of two faunal subprovinces in the seaway. The Northern Interior Subprovince is characterized by a low diversity in all groups and is dominated by plesiosaurs, hesperornithiforms and the mosasaur Platecarpus. The Southern Interior Subprovince is characterized by a high diversity in all groups and is dominated by sharks, turtles and the mosasaur Clidastes. These biogeographical subdivisions support the hypothesis of warm temperature and cool temperate zones in the seaway that have been proposed on the basis of invertebrate faunas.
Anatomical abbreviations: bic ¼ bicipital crest, ext tub ¼ external tuberosity, dpc ¼ deltopectoral crest, fo ¼ pit-shaped fossa, gl h ¼ globose head, int con ¼ internal condyle, int tub ¼ internal tuberosity On the occurrence of Gillicus arcuatus (Cope, 1875) (Pisces, Ichthyodectiformes) in Mexico
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C, composite restoration of right humerus of I. dispar in posterior view (after Marsh, 1880) from Niobrara Chalk of Kansas. Anatomical abbreviations: bic ¼ bicipital crest, ext tub ¼ external tuberosity, dpc ¼ deltopectoral crest, fo ¼ pit-shaped fossa, gl h ¼ globose head, int con ¼ internal condyle, int tub ¼ internal tuberosity, olc ¼ olecranon fossa. H.G. Porras-Múzquiz et al. / Cretaceous Research 51 (2014) 148e152 References Alvarado-Ortega, J., Porras-Múzquiz, H., 2009. On the occurrence of Gillicus arcuatus (Cope, 1875) (Pisces, Ichthyodectiformes) in Mexico. Boletín de la Sociedad Geol ogica Mexicana 61, 215e224. Alvarado-Ortega, J., Porras-Múzquiz, H., 2012. The first American record of Aspi-dopleurus (Teleostei, Aulopiformes) from La Mula Quarry. Revista Brasileira de Paleontologia 15, 251e263. Blanco-Pi~ n on, A., Alvarado-Ortega, J., 2005. Fishes from La Mula Quarry, a new Late Cretaceous locality from the vicinity of Múzquiz, Coahuila, NE M exico. In: Poyato-Ariza, F.J. (Ed.), Fourth International Meeting on Mesozoic Fishes-Systematics, Homology, and Nomenclature-Extended Abstracts, UAM ediciones, Espa~ na, pp. 37e40. Clarke, J.A., 2004. Morphology, phylogenetic taxonomy, and systematics of Ich-thyornis and Apatornis. Bulletin of the American Museum of Natural History 286, 1e179.
Odontornithes: a monograph on the extinct toothed birds of North America. Report of the United States Geological Survey; Exploration of the 40th Parallel
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Marsh, O.C., 1880. Odontornithes: a monograph on the extinct toothed birds of North America. Report of the United States Geological Survey; Exploration of the 40th Parallel, 201 p.
Fishes from La Mula Quarry, a new Late Cretaceous locality from the vicinity of Múzquiz
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Blanco-Piñ on, A., Alvarado-Ortega, J., 2005. Fishes from La Mula Quarry, a new Late Cretaceous locality from the vicinity of Múzquiz, Coahuila, NE M exico. In: Poyato-Ariza, F.J. (Ed.), Fourth International Meeting on Mesozoic Fishes-Systematics, Homology, and Nomenclature-Extended Abstracts, UAM ediciones, España, pp. 37e40.
Fossil fish assemblages of northeastern Mexico: new evidence of mid Cretaceous Actinopterygian radiation
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Giersch, S., Frey, E., Stinnesbeck, W., Gonz alez-Gonz alez, A.H., 2008. Fossil fish assemblages of northeastern Mexico: new evidence of mid Cretaceous Actinopterygian radiation. In: Meeting of the European Association of Vertebrate Paleontology 6, Abstracts, Spi ssk a Nov a Ves, pp. 43e45.
A new lithographic limestone deposit in the Upper Cretaceous Austin Group at El Rosario, county of Múzquiz
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Stinnesbeck, W., Ifrim, C., Schmidt, H., Rindfleich, A., Buchy, M.C., Frey, E., Gonz alez-Gonz alez, A., Vega, V.F., Cavin, L., Keller, G., Smith, K.T., 2005. A new lithographic limestone deposit in the Upper Cretaceous Austin Group at El Rosario, county of Múzquiz, Coahuila, northeastern Mexico. Revista Mexicana de Ciencias Geol ogicas 22, 401e418.