[Paleontology • 2025] Kostensuchus atrox • A New large hypercarnivorous Crocodyliform (Mesoeucrocodylia: Peirosauridae) from the Maastrichtian of Southern Patagonia, Argentina

 

Kostensuchus atrox

Novas, Pol, Agnolín, Carvalho, Manabe, Tsuihiji, Rozadilla, Lio & Isasi, 2025

  

DOI: doi.org/10.1371/journal.pone.0328561

Abstract

The first crocodyliform specimen from the Maastrichtian Chorrillo Formation (Austral Basin, Patagonia) is here described. The discovery was made about 30 km to the SW of the town of El Calafate (Province of Santa Cruz, Argentina) and consists of a beautifully preserved and articulated skull and jaws, and part of the postcranial skeleton that were preserved encased in a large concretion. This new taxon belongs to the notosuchian clade Peirosauridae, representing the latest and southernmost record for this group of crocodyliforms. The new taxon is recovered as closely related to other robust and broad-snouted peirosaurids that lived by the end of the Cretaceous Period, such as Colhuehuapisuchus from the Maastrichtian of Central Patagonia and Miadanasuchus oblita from the Maastrichtian of Madagascar. The completeness of the new specimen reveals, for the first time, the anatomy and body plan of a large and broad snouted peirosaurid. The new taxon bears large ziphodont teeth, a broad oreinirostral snout that is only slightly longer than 50% the skull length, and a deep adductor chamber in the temporal region and posterior mandibular ramus. The anterior region of its postcranial skeleton is preserved and shows broad scapula and a robust humerus features previously known in large predatorial notosuchians. The new crocodyliform adds to the predatorial component of terrestrial ecosystems at high paleolatitudes by the end of the Cretaceous Period.

Systematic paleontology

Crocodyliformes Hay, 1930

Mesoeucrocodylia Whetstone and Whybrow, 1980

Peirosauria Leardi et al., 2024

Peirosauridae Gasparini, 1982

Kostensuchus atrox gen. et sp. nov.

Etymology. Kosten, refers to the Patagonian wind in Aonikenk language; and suchus, latinized from the Greek Souchos in references to the Egyptian crocodile-headed god (Sebek). The species epithet atrox means harsh in Greek.

Holotype. MPM-PV 23554, articulated skull, jaws, cervical, axial skeleton remains including cervical, dorsal, and sacrals, rows of osteoderms along the vertebral sequence, cervical and dorsal ribs, scapular and pelvic girdles, complete right humerus and partial left humerus, and fragmentary remains of the hindlimbs.

Locality, horizon, and age. Lower section of the Chorrillo Formation, at Estancia La Anita, approximately 30 km SW from El Calafate city (Fig 1). The specimen comes from a concretionary level exposed at the locality “Puma cave” (locality 4, 5), approximately 60 meters from the base of the Chorrillo Formation.

Diagnosis. Kostensuchus gen. nov. is among the largest known peirosaurids (dorsal skull length = 49 cm) diagnosed by the following combination of characters (autapomorphies marked by *): skull proportionally shorter, wider and higher than in other peirosaurids (e.g., Hamadasuchus, Lomasuchus, Montealtosuchus); rostrum comprising slightly over 50% the total skull length; sinusoidal alveolar margin of maxilla (shared with Hamadasuchus); completely ossified internarial bar; lacrimal lateral surface faintly ornamented and slightly depressed between antorbital fenestra and orbit*; jugal reaching the ventral end of a circular antorbital fenestra; subtrapezoidal external supratemporal fenestra, occupying close to 70% of skull roof width; absence of anterior floor of supratemporal fossa; flat dorsal surface of parietal in occipital view; distinct step on dorsal surface of the posterolateral process of squamosal; broad palatine anterior margin, forming a bread transversal suture with maxilla; paired parasagittal ridges on the ventral surface of the basisphenoid; convex dorsal edge of surangular and craniomandibular articulation located above the level of dentary toothrow; ziphodont teeth; humerus with vertical orientation of insertion area of M. subscapularis above internal tuberosity; distal end of deltopectoral crest curves medially surpassing the lateromedial midpoint of humeral shaft; anterior surface of distal end of humerus separated from shaft by a distinct step forming a shelf.

Skull and jaw of Kostensuchus atrox gen. et sp. nov.
Photographs in (A) right lateral, (B) dorsal, and (C) ventral views. Interpretative drawings in (D) right lateral, (E) dorsal, and (F) ventral views.

 Abbreviations: ang, angular; ap, anterior palpebral; de, dentary; ec, ectopterygoid; fr, frontal; j, jugal; la, lacrimal; mx, maxilla; pa, parietal; pal, palatine; pmx, premaxilla; pnf, perinarial fossa; po, postorbital; pp, posterior palpebral; pt, pterygoid; q, quadrate; qj, quadratojugal; na, nasal; rarp, retroarticular process; sang, surangular; sof, suborbital fossa; spl, splenial; sq, squamosal; stf, subtympanic foramen. Scale bar 5 cm.

 

 Fernando E. Novas, Diego Pol, Federico L. Agnolín, Ismar de Souza Carvalho, Makoto Manabe, Takanobu Tsuihiji, Sebastián Rozadilla, Gabriel L. Lio and Marcelo P. Isasi. 2025. A New large hypercarnivorous Crocodyliform from the Maastrichtian of Southern Patagonia, Argentina. PLoS One. 20(8): e0328561.  DOI: doi.org/10.1371/journal.pone.0328561 [August 27, 2025]

 

[Paleontology • 2019] Portugalosuchus azenhae • A New Eusuchian Crocodylomorph from the Cenomanian (Late Cretaceous) of Portugal reveals Novel Implications on the Origin of Crocodylia

Portugalosuchus azenhae 

Mateus, Puértolas-Pascual & Callapez, 2019

DOI: doi.org/10.1093/zoolinnean/zly064

Abstract

The fossil record of Eusuchia extends back to the Early Cretaceous (Barremian), with the English species Hylaeochampsa vectiana being the oldest known representative of the clade so far. However, the eusuchian record from the Barremian to the Santonian is scarce and fragmentary worldwide. Here we described a new eusuchian crocodylomorph based on a partial skull and lower jaw from the Early Upper Cenomanian of the Tentugal Formation, in the Baixo Mondego region, west-central Portugal. The specimen exhibits a series of characters not seen in other taxa, allowing its assignment to a new genus and species named Portugalosuchus azenhae gen. et sp. nov. The results of a cladistic analysis place this specimen within Crocodylia, as the sister taxon to all other non-gavialoid crocodylians. Therefore, this Portuguese specimen represents the only well-documented and valid eusuchian species in the Cenomanian in Europe, and may be the oldest representative of Crocodylia known so far, helping to fill a gap in the fossil record of Eusuchia from the Barremian to the Campanian. In addition, the discovery of this new taxon sheds light on the radiation of Eusuchia and the origin of Crocodylia, which probably took place in Europe.  

Crocodylomorpha, Eusuchia, phylogeny, systematics

 

  

  

Octávio Mateus, Eduardo Puértolas-Pascual and Pedro M Callapez. 2019. A New Eusuchian Crocodylomorph from the Cenomanian (Late Cretaceous) of Portugal reveals Novel Implications on the Origin of Crocodylia. Zoological Journal of the Linnean Society, zly064.  DOI: doi.org/10.1093/zoolinnean/zly064 

 

Descoberto em Portugal o mais antigo crocodilo fóssil do mundo tsf.pt/sociedade/interior/descoberto-em-portugal-o-mais-antigo-crocodilo-fossil-do-mundo-10286846.html

Portugalosuchus: Paleontólogos portugueses descobrem nova espécie: o mais antigo crocodilo fóssil conhecido dct.fct.unl.pt/investigacao/portugalosuchus

Paleontólogos portugueses descobrem o mais antigo crocodilo fóssil do mundo em Tentúgal: observador.pt/2018/12/06/paleontologos-portugueses-descobrem-o-mais-antigo-crocodilo-fossil/ via @observadorpt

Paleontologia. O fóssil de crocodilo mais antigo do mundo é de Tentúgal publico.pt/2018/12/06/ciencia/noticia/fossil-crocodilo-antigo-mundo-tentugal-1853821

[Paleontology • 2024] Cranial Anatomy of Acynodon adriaticus and extreme durophagous adaptations in Eusuchia (Reptilia: Crocodylomorpha)

 

Acynodon adriaticus Delfino, Martin & Buffetaut, 2008

in Muscioni, Chiarenza, Fernandez, Dreossi, Bacchia et Fanti. 2024.   

DOI: doi.org/10.1002/ar.25574

  facebook.com/AnatomicalRecord

Artwork by Davide Bonadonna   facebook.com/DavideBonadonna1

Abstract

Acynodon adriaticus, a small eusuchian from the Late Cretaceous of Italy, is known for its well-preserved cranial and postcranial material. Despite its excellent preservation, many details remain hidden due to the physical overlap between the elements and matrix obliteration. We used Micro-CT scans to reveal previously overlooked anatomical features and describe in detail the cranial and dental anatomy of this taxon, shedding new light on its palaeoecology. The holotypic specimen, SC 57248, represents a mature individual exhibiting signs of hyperossification, developed ornamentation, and various pathologies, including jaw arthritis and a possible dental anomaly. Acynodon adriaticus exhibits significant durophagous adaptations, including a robust, brevirostrine skull optimized for powerful biting and stress-load capacity. Its specialized dentition, lacking caniniform teeth, features anterior chisel-like teeth and hypertrophic posterior molariforms with thick enamel, indicative of a diet specializing in hard-shelled prey. The dentition pattern, accelerated molariform replacement rate, and reduced orbit size suggest adaptations for durophagous foraging in turbid, densely vegetated aquatic environments. The paleoecological context during the Late Cretaceous, characterized by increased freshwater habitats and high invertebrate diversity, likely facilitated the evolution of such specialized traits in A. adriaticus. This small crocodylomorph likely foraged slowly in shallow, benthic environments, using its powerful bite to process mollusks and large arthropods. The study of A. adriaticus, along with comparisons with other crocodylomorphs and ecomorphologically similar taxa like Iharkutosuchus makadii and Gnatusuchus pebasensis, provides a valuable morphofunctional model for understanding the evolutionary pathways of extinct crocodylians to durophagy.

Keywords: Acynodon, Cretaceous, durophagy, Hylaeochampsidae, paleobiology

  Systematic paleontology

Crocodylomorpha Hay, 1930 sensu Nesbitt, 2011.

Neosuchia Benton & Clark, 1988.

Eusuchia Huxley, 1875 sensu Brochu, 2003.

Hylaeochampsidae Andrews, 1913.

Acynodon Buscalioni et al., 1997.

Acynodon adriaticus Delfino et al., 2008.

Schematic individual cranial bones of MCSNT 57248 in dorsal (a), ventral (b), lateral (c) and posterior (d) view. ...

 

Marco Muscioni, Alfio Alessandro Chiarenza, Diego Bladimir Haro Fernandez, Diego Dreossi, Flavio Bacchia, Federico Fanti. 2024. Cranial Anatomy of Acynodon adriaticus and extreme durophagous adaptations in Eusuchia (Reptilia: Crocodylomorpha). The Anatomical Record. DOI: doi.org/10.1002/ar.25574

  facebook.com/AnatomicalRecord/posts/1042639271202269

  facebook.com/DavideBonadonna1/posts/1077033717762273

Nuove scoperte sul fossile di un coccodrillo di 80 milioni di anni al Villaggio del Pescatore

 www.nationalgeographic.it/nuove-scoperte-sul-fossile-di-un-coccodrillo-di-80-milioni-di-anni-al-villaggio-del-pescatore

[Paleontology • 2024] Enalioetes schroederi • A New Genus of metriorhynchid crocodylomorph from the Lower Cretaceous of Germany

Enalioetes schroederi 

Sachs, Young, Hornung, Cowgill, Schwab & Brusatte, 2024

 

 DOI: 10.1080/14772019.2024.2359946  

 

Abstract

Here we describe a new genus and species of metriorhynchid crocodylomorph, Enalioetes schroederi gen. et sp. nov., from the lower Valanginian Stadthagen Formation (Lower Cretaceous) of north-western Germany. Enalioetes schroederi is the most complete and well-preserved Cretaceous metriorhynchid skull known to date, preserving most of the cranium and mandible, the atlas-axis complex and the first postaxial cervical vertebra. The specimen was previously attributed to the coeval enigmatic metriorhynchid Enaliosuchus (a nomen dubium) and, more recently, to Cricosaurus. Although the specific epithet schroederi has been used frequently in the literature, it has never been formally established. Herein, we demonstrate that the new taxon is distinct from all known metriorhynchids by a unique combination of characters including several autapomorphies such as: the lack of bulbous dorsolateral expansion in the posterior nasal cavity; mediolateral distance between the orbital canals being approximately 1.5 times the diameter of the orbital canals; lacrimal with dorsoventrally deep anterior process ventral to the preorbital fossa being equal to or greater than the depth of the jugal anterior process and the anterodorsal process of the lacrimal; and ascending processes at atlas intercentrum extending far dorsally to level of neural canal. Enalioetes schroederi contributes to the sparse global record of Cretaceous metriorhynchids and represents one of the stratigraphically youngest occurrences of the group. It can thus help to enhance our understanding of the metriorhynchid diversity during the Cretaceous Period. 

Keywords: Metriorhynchidae, Thalattosuchia, Cretaceous, taxonomy, Germany

 

  Enalioetes schroederi

Sven Sachs, Mark T. Young, Jahn J. Hornung, Thomas Cowgill, Julia A. Schwab and Stephen L. Brusatte. 2024. A New Genus of metriorhynchid crocodylomorph from the Lower Cretaceous of Germany. Journal of Systematic Palaeontology. 22(1);  2359946. DOI: doi.org/10.1080/14772019.2024.2359946  

[Paleontology • 2024] Araripesuchus manzanensis • A New Species of Araripesuchus with durophagous dentition increases the ecological disparity among uruguaysuchid crocodyliforms

Araripesuchus manzanensis

Dumont, Pol, Bona & Apesteguía. 2024. 

DOI: 10.1080/14772019.2024.2373987 

 

Abstract

Notosuchia is a group of crocodyliforms with mostly terrestrial habits that lived during the Mesozoic and up to the Miocene. Within this group Uruguaysuchidae is so far represented by eight species, six of them clustered in the genus Araripesuchus. Two species of this genus, A. patagonicus and A. buitreraensis, come from different localities in Patagonia (Argentina) from the Candeleros Formation (Cenomanian age). Here we present a third species of Araripesuchus from this formation. The new species comes from the same locality as Araripesuchus buitreraensis, but differs in numerous features including the presence of different molariform teeth. The new species was included in a phylogenetic analysis and, in agreement with previous analyses, Uruguaysuchidae is recovered as monophyletic and placed within Notosuchia as the sister clade of Peirosauridae. Uruguaysuchidae includes all species of Araripesuchus as well as Anatosuchus minor and Uruguaysuchus aznarezi. The new species adds new information to the ecological diversity of the group its bulbous molariforms with a quadrangular occlusal surface bounded by mamelons is interpreted as indicative of a durophagous diet, suggesting the presence of niche partitioning between the two sympatric species A. manzanensis and A. buitreraensis.  

Keywords: Notosuchia, Araripesuchus, Patagonia, La Buitrera, durophagous diet, niche partitioning

 

María Lucila Fernández Dumont, Diego Pol, Paula Bona and Sebastián Apesteguía. 2024. A New Species of Araripesuchus with durophagous dentition increases the ecological disparity among uruguaysuchid crocodyliforms. Journal of Systematic Palaeontology. 22(1);  2373987. DOI: doi.org/10.1080/14772019.2024.2373987 

[Paleontology • 2024] Caipirasuchus catanduvensis • A New Species of vocalizing Crocodyliform (Notosuchia: Sphagesauridae) from the Late Cretaceous of Brazil

 

Caipirasuchus catanduvensis 

 Iori, Ghilardi, Fernandes & Dias, 2024

DOI: 10.1080/08912963.2024.2364332

 x.com/AlineMGhilardi

ABSTRACT

Caipirasuchus is a genus of sphagesaurid notosuchian from the Bauru Basin (Upper Cretaceous), southeast Brazil. They were small-sized herbivorous/omnivorous animals, that measured around 1 metre in length, and had a wide diversity and geographical dispersion in the basin. Here, we diagnosed the 6th species of the genus, originating from sandstones of the Adamantina Formation in the municipality of Catanduva, São Paulo State. Caipirasuchus presents a significant variation in the morphology of structures in the choana region. In particular, the new species has chambers in the wings of the pterygoids that connect with an extension of the airways, suggesting a region of resonance used in vocalisation. The different palatal structures in Caipirasuchus may be related to distinct bioacoustic signatures and indicate apossible improvement in the social organisation of Caipirasuchus.

KEYWORDS: Crocodylomorpha, crocodyliformes, Adamantina formation, bioacoustics, vocalization, Bauru Basin

Caipirasuchus catanduvensis 

Fabiano V. Iori, Aline M. Ghilardi, Marcelo A. Fernandes and Willian A.F. Dias. 2024. A New Species of vocalizing Crocodyliform (Notosuchia, Sphagesauridae) from the Late Cretaceous of Brazil. Historical Biology: An International Journal of Paleobiology. DOI: 10.1080/08912963.2024.2364332

 x.com/AlineMGhilardi/status/1801587794671726791

[Paleontology • 2024] Ophiussasuchus paimogonectes • A New goniopholidid Crocodylomorph (Crocodylomorpha: Goniopholididae) from the Late Jurassic of Portugal

Ophiussasuchus paimogonectes

López-Rojas, Mateus, Marinheiro, Mateus, & Puértolas-Pascual, 2024

DOI: 10.26879/1316 

twitter.com/PalaeoE

ABSTRACT

Plenty of goniopholidid species from the Mesozoic have been found in the Iberian Peninsula. A previous goniopholidid taxon, Goniopholis baryglyphaeus Schwarz, 2002, from the Late Jurassic of the Guimarota coal mine (Leiria, central Portugal) was described. This taxon corresponds to a partial skull and some postcranial material, and it marked the oldest and first ever record of goniopholidid and Goniopholis species described for the Iberian Peninsula. Here we present a well-preserved, almost complete, skull of a new species, Ophiussasuchus paimogonectes gen. et sp. nov. from Upper Jurassic deposits of Praia de Paimogo (near Lourinhã, central west Portugal). The specimen corresponds to a mesorostrine, platyrostral skull of a medium-sized goniopholidid coming from the upper Kimmeridgian within the Lourinhã Formation. Phylogenetically, the new species is recovered as the sister taxon of the Early Cretaceous European clade made by Hulkepholis and Anteophthalmosuchus. Although its position is well-resolved, this new taxon displays intermediate morphological traits, sharing characteristics with Jurassic Asian and American basal goniopholidids (e.g., presence but lesser development of the secondary choana with the nasopharyngeal duct partially open), as well as more derived characters shared with Cretaceous European taxa such as Hulkepholis (e.g., the shape of the supratemporal fenestra and the palatines). As a result, Ophiussasuchus paimogonectes gen. et sp. nov. exhibits characteristics suggesting a reversion to primitive goniopholidid conditions or intermediate states between the goniopholidid taxa of North America and Europe. These findings support the shared Late Jurassic fauna between the Morrison and Lourinhã Formations, while also having high endemism of taxa.

Keywords: new genus; new species; Lourinhã Formation; upper Kimmeridgian; Crocodylomorpha; phylogeny

 Skull of ML2776 Ophiussasuchus paimogonectes gen. et sp. nov. 

Anatomical abbreviations: f, frontal; itf, infratemporal fenestra; j, jugal; lac, lacrimal; mx, maxilla; mx.dp, maxillary depressions; n, nasal; o, orbit; pa, parietal; pal, palpebral; pf, prefrontal; pmx, premaxilla; po, postorbital; q, quadrate; qj, quadratojugal; sq, squamosal; stf, supratemporal fenestra; t, tooth. 

Scale represents 10 cm.

 Skull of ML2776 Ophiussasuchus paimogonectes gen. et sp. nov., in lateral view.

Anatomical abbreviations: ec, ectopterygoid; j, jugal; mx, maxilla; mx.dp, maxillary depressions; n, nasal; pal, palpebral; pf, prefrontal; pmx, premaxilla; po, postorbital; pt, pterygoid; q, quadrate; qj, quadratojugal; sq, squamosal; t, tooth. 

Scale represents 10 cm.

SYSTEMATIC PALEONTOLOGY

Superorder CROCODYLOMORPHA Hay, 1930 (sensu Walker, 1970)

Clade CROCODYLIFORMES Hay, 1930

Suborder MESOEUCROCODYLIA Whetstone and Whybrow, 1983 (sensu Benton and Clark, 1988)

Infraoder NEOSUCHIA Gervais, 1871 (sensu Benton and Clark, 1988)

Family GONIOPHOLIDIDAE Cope, 1875

Genus OPHIUSSASUCHUS gen. nov.

Etymology. ‘ Ophiussa ’ refers to the ancient name given by the Greeks to the area where is now Portugal; and ‘ suchus ’ is from the Greek souchos that refers to crocodile-headed Egyptian god Sobek.

OPHIUSSASUCHUS PAIMOGONECTES sp. nov

 

Holotype. ML2776, an almost complete and well-preserved isolated skull, with some teeth still attached. The specimen is deposited at Lourinhã Museum (Museu da Lourinhã), Lourinhã, Portugal.

Etymology. ‘paimogonectes’ refers to the one who swims in Paimogo, where the specimen was found (Paimogo beach, Lourinhã, Portugal).

Age and horizon. Praia Azul Member, Lourinhã Formation, Lusitanian Basin, west coast of Portugal. upper Kimmeridgian-lower Tithonian, Upper Jurassic.

Type locality. Praia de Paimogo (GPS coordinates: 39° 17’ 10.4” N, 9° 20 ’17.4” W), Lourinhã, Lisbon, Portugal.

Diagnosis. Medium-sized crocodylomorph about 2.5 m to 3 m long (estimated body length based on Young et al., 2011), with platyrostral, mesorostrine skull and a marked festooned contour which differs from other goniopholidids since it possess a less pronounced axe-shaped premaxillae dorsal outline; smooth perinarial region with absence of crests around it; presence of different number of maxillary depressions between the left and right regions (four and five, respectively); anteriorly well-marked V-shape border of the palatines in contact with the maxillae; nasals with straight, sub-parallel margins between the maxillae, with little to no lateral expansion at their posterior-most border; main body of the frontal with sub-squared shape in dorsal view, without lateral expansion; nasopharyngeal duct less ventrally exposed than in Jurassic taxa (e.g., Calsoyasuchus or Eutretauranosuchus) but not as closed as in Cretaceous taxa (e.g., Hulkepholis or Anteophthalmosuchus); presence of two small, thin, anteroposteriorly elongated and crescent-shaped palatal fenestrae between the maxillae and the palatines.

CONCLUSIONS: 

A new and the most complete skull of crocodylomorph (ML2776) from the Late Jurassic of Lourinhã Fm, was recovered and is here described as a new genus and species, Ophiussasuchus paimogonectes gen. et sp. nov.

This new taxon was recovered with a unique combination of 15 synapomorphies. These synapomorphies are a combination of features from both older North American and younger European taxa, such as the shape of the rostrum with a less-projected axe shape compared with Jurassic North American species (Amphicotylus) and more similar to Cretaceous taxa, while the nasopharyngeal duct openings are more closed than older species (Calsoyasuchus or Eutretauranosuchus) but not completely closed as in Hulkepholis and Anteophthalmosuchus, with which Ophiussasuchus paimogonectes gen. et sp. nov. has closer relationships. In addition, ML2776 displays an asymmetrical number of maxillary fossae (four in the left region while five in the right region). However, any hypothesis regarding this asymmetry cannot be contrasted until more specimens are found.

The new taxon Ophiussasuchus paimogonectes gen. et sp. nov. increases the already high paleodiversity of crocodylomorphs of the locality. It also supports the hypothesis of a shared fauna between North America (Morrison Fm) and Western Europe (Lourinhã Fm) during the Late Jurassic, as well as the high endemism of Portugal, distinguishing both continents.

 

Víctor López-Rojas, Simão Mateus, João Marinheiro, Octávio Mateus, and Eduardo Puértolas-Pascual. 2024. A New goniopholidid Crocodylomorph from the Late Jurassic of Portugal. Palaeontologia Electronica, 27(1):a5. DOI: 10.26879/1316

 twitter.com/PalaeoE/status/1748174557784014940

[Paleontology • 2024] Varanosuchus sakonnakhonensis • New Cretaceous neosuchians (Crocodylomorpha) from Thailand bridge the evolutionary history of atoposaurids and paralligatorids

Varanosuchus sakonnakhonensis 

Pochat-Cottilloux, Lauprasert, Chanthasit, Manitkoon, Adrien, Lachambre, Amiot & Martin, 2024

วาราโนซูคัส สกลนครเอนซิส  || DOI: 10.1093/zoolinnean/zlad195

 twitter.com/YohanPochatCot

  facebook.com/Lauprasert

Abstract

The origin of modern crocodylians is rooted in the Cretaceous, but their evolutionary history is obscure because the relationships of outgroups and transitional forms are poorly resolved. Here, we describe a new form, Varanosuchus sakonnakhonensis gen. nov., sp. nov., from the Early Cretaceous of Thailand that fills an evolutionary gap between Paralligatoridae and Atoposauridae, two derived neosuchian lineages with previously unsettled phylogenetic relationships. Three individuals, including a complete skull and associated postcranial remains, allow for a detailed description and phylogenetic analysis. The new taxon is distinguished from all other crocodylomorphs by an association of features, including a narrow altirostral morphology, a dorsal part of the postorbital with an anterolaterally facing edge, a depression on the posterolateral surface of the maxilla, and fully pterygoid-bound choanae. A phylogenetic analysis confirms the monophyly and taxonomic content of Atoposauridae and Paralligatoridae, and we underline the difficulty in reaching a robust definition of Eusuchia. Furthermore, we put forward further arguments related to the putative terrestrial ecology with semi-aquatic affinities of atoposaurids based on their altirostral snout morphology and osteoderm ornamentation.

Atoposauridae, CT scan, Neosuchia, Phu Sung, Sao Khua, Thailand

Varanosuchus sakonnakhonensis gen. nov., sp. nov.

 

Yohan Pochat-Cottilloux, Komsorn Lauprasert, Phornphen Chanthasit, Sita Manitkoon, Jérôme Adrien, Joël Lachambre, Romain Amiot and Jeremy E Martin. 2024. New Cretaceous neosuchians (Crocodylomorpha) from Thailand bridge the evolutionary history of atoposaurids and paralligatorids. Zoological Journal of the Linnean Society. zlad195. DOI: 10.1093/zoolinnean/zlad195

 twitter.com/YohanPochatCot/status/1744994803845083179

  facebook.com/Lauprasert/posts/10161145090367162

วาราโนซูคัส สกลนครเอนซิส  🐊🐊

จระเข้ทรงเหี้ย จระเข้ดึกดำบรรพ์ชนิดใหม่ชนิดที่ 12 ของประเทศไทย  

 จากหมวดหินเสาขัว ต้นยุคครีเทเชียส จ.สกลนคร 

[Paleontology • 2023] Evaluating Growth in Macrospondylus bollensis (Crocodylomorpha: Teleosauroidea) in the Toarcian Posidonia Shale, Germany

Macrospondylus bollensis  Jäger, 1828

in Johnson, Amson & Maxwell, 2023.

DOI: 10.1002/spp2.1529 

 twitter.com/Michela_Johnson

 www.naturkundemuseum-bw.de

Abstract

The study of how organisms grow is a fundamental aspect of palaeontology. Growth in teleosauroids is poorly understood and little studied, especially in an ontogenetic sense. We investigate growth rates of the most common and abundant teleosauroid, Macrospondylus bollensis, in which a large sample of multiple body sizes is available from the Posidonienschiefer Formation (Posidonia Shale) of southwestern Germany. We perform linear regression analyses on 62 specimens of Macrospondylus (16 juveniles, 7 subadults and 39 adults) using 21 cranial and postcranial measurements. Our results show that juvenile, subadult and adult individuals have near-isometric or isometric growth throughout much of the body. Notably, we find that in Macrospondylus: (1) the femur grows at a faster rate than the skull and hindlimb zeugopodium; (2) the forelimb and hindlimb grow at the same rate; and (3) there is distinct ontogenetic signal in the growth of the orbit and supratemporal fenestra. We also find that limb scaling in Macrospondylus is somewhat comparable to that seen in the extant gavialids Gavialis gangeticus and Tomistoma schlegelii. Last, we examine evolutionary allometry in skull length relative to body size in Crocodylomorpha using femoral length as a proxy, which shows a near-isometric trend. Non-thalattosuchian crocodylomorphs (with the exception of one pholidosaurid and one dryosaurid taxon) are differentiated from thalattosuchians due to their shorter skulls, as previously suggested, but the scaling relationship with femur length remains unchanged.

Keywords: Teleosauroidea, Crocodylomorpha, evolutionary allometry, ontogenetic allometry, Macrospondylus bollensis, Posidonia Shale Formation

 

Michela M. Johnson, Eli Amson and Erin E. Maxwell. 2023. Evaluating Growth in Macrospondylus bollensis (Crocodylomorpha, Teleosauroidea) in the Toarcian Posidonia Shale, Germany. Papers in Palaeontology. DOI: 10.1002/spp2.1529

  twitter.com/Michela_Johnson/status/1712128784130879786

 www.naturkundemuseum-bw.de/en/press/detailansicht/studie-zum-groessenwachstum-von-meereskrokodilen-in-der-jurazeit

  phys.org/news/2023-10-size-growth-marine-crocodiles-jurassic.html

[Paleontology • 2023] Turnersuchus hingleyae • A New early Diverging thalattosuchian (Crocodylomorpha: Thalattosuchia) from the Early Jurassic (Pliensbachian) of Dorset, U.K. and Implications for the Origin and Evolution of the Group

Turnersuchus hingleyae

Wilberg, Godoy, Griffiths, Turner & Benson,  2023

DOI: 10.1080/02724634.2022.2161909 

 twitter.com/PedroLGodoy 

Illustration: Júlia d'Oliveira twitter.com/tupandactylus 

ABSTRACT

Among archosaurs, thalattosuchian crocodylomorphs experienced the most extensive adaptations to the marine realm. Despite significant attention, the phylogenetic position of the group remains uncertain. Thalattosuchians are either the sister-group to Crocodyliformes, basal mesoeucrocodylians, or nest among longirostrine neosuchians. The earliest definite thalattosuchians are Toarcian, and already possess many synapomorphies of the group. All phylogenetic hypotheses imply a ghost lineage extending at least to the Sinemurian, and a lack of older or more plesiomorphic forms may contribute to the uncertain phylogenetic placement of the group. Here we describe a new species, Turnersuchus hingleyae, gen. et sp. nov., from the early Pliensbachian Belemnite Marl Member of the Charmouth Mudstone Formation (Dorset, U.K.). The specimen includes partially articulated cranial, mandibular, axial, and appendicular elements. It can be attributed to Thalattosuchia based on the following features: distinct fossa on the posterolateral corner of the squamosal; broad ventrolateral process of the otoccipital covering the dorsal surface of the quadrate; large supratemporal fenestrae lacking a flattened skull table; broadly exposed prootic; orbital process of quadrate lacking bony attachment with the braincase. This specimen represents the earliest thalattosuchian currently known from diagnostic material. Phylogenetic analyses of two published datasets recover Turnersuchus as the earliest diverging thalattosuchian, and sister to Teleosauroidea + Metriorhynchoidea. Bayesian tip-dating analyses suggest a Rhaetian or Sinemurian divergence of Thalattosuchia from other crocodylomorphs, depending on topology, with confidence intervals spanning from the Norian to the Pliensbachian. The new specimen extends the fossil record of Thalattosuchia, but the time-scaling analyses demonstrate that a significant ghost lineage remains.

 Turnersuchus hingleyae, gen. et sp. nov.

 

Eric W. Wilberg, Pedro L. Godoy, Elizabeth F. Griffiths, Alan H. Turner and Roger B. J. Benson. 2023. A New early Diverging thalattosuchian (Crocodylomorpha) from the Early Jurassic (Pliensbachian) of Dorset, U.K. and Implications for the Origin and Evolution of the Group. Journal of Vertebrate Paleontology.  e2161909. DOI: 10.1080/02724634.2022.2161909  

  twitter.com/PedroLGodoy/status/1616568227936538624

[Paleontology • 2023] The Vertebrate Fossil Record from the Feliz Deserto Formation (Lower Cretaceous), Sergipe, NE Brazil: Paleoecological, Taphonomic, and Paleobiogeographic Implications

in Lacerda, de Andrade, Sales, Aragão, ... et Liparini, 2023. 

DOI: 10.1016/j.cretres.2022.105463

 Highlights: 

• Increase of knowledge about Lower Cretaceous archosaurs from Brazil.

• First crocodyliform fossil findings of the Feliz Deserto Formation.

• Additional records of the oldest Gondwanan spinosaurine theropods.

• Paleoenvironmental characterization of Canafístula 01 fossiliferous locality.

Abstract

The Feliz Deserto Formation (Berriasian–Valanginian, Sergipe-Alagoas Basin, NE Brazil) preserved some of the earliest South American fossil records of the rifting stages which resulted in the Gondwana supercontinent break-up during the Lower Cretaceous. Recently, the first spinosaurid theropod record of this formation was described, based on a tooth recovered from Canafístula 01 fossil locality in Sergipe State. We add herein twenty-seven isolated specimens to the fossil record of the Lower Cretaceous Feliz Deserto Formation. The new material includes seven isolated spinosaurid theropod teeth of the spinosaurine clade, as well as an indeterminate theropod preungual pedal phalanx. In addition, we describe an isolated crocodyliform osteoderm, as well as eighteen isolated teeth, some of which were taxonomically identified in three distinct morphotypes of neosuchian crocodyliforms. These findings expand the Gondwanan fossil record of both spinosaurine theropods and neosuchian crocodyliforms. Despite the fragmented nature of the specimens, these new fossils allowed the characterization of their general taphonomic features with low fluvial transport of bioclast prior to the burial. The depositional paleoenvironment of the Canafístula 01 locality is compatible with the deltaic system unit, that characterizes part of the Feliz Deserto Formation during the Lower Cretaceous. These fossil findings exemplify the co-occurrence of spinosaurids and more than one taxon of crocodyliforms in the deltaic-lacustrine paleoenvironment represented by the Feliz Deserto Formation. These new occurrences reinforce the fossiliferous potential of the Canafístula 01 locality, especially related to the paleovertebrates from the Lower Cretaceous of Brazil.

 

Keywords: Berriasian–Valanginian, Mesoeucrocodylia, Paleovertebrates, Sergipe-Alagoas Basin, Spinosauridae, Theropoda

Mauro B.S. Lacerda, Marco B. de Andrade, Marcos A.F. Sales, Paulo R.L. Aragão, Fabiana S. Vieira, Jonathas S. Bittencourt and Alexandre Liparini. 2023. The Vertebrate Fossil Record from the Feliz Deserto Formation (Lower Cretaceous), Sergipe, NE Brazil: Paleoecological, Taphonomic, and Paleobiogeographic Implications. Cretaceous Research. In Press. DOI: 10.1016/j.cretres.2022.105463

[Paleontology • 2022] Titanochampsa iorii • A Large-sized Mesoeucrocodylian (Crocodylomorpha: Mesoeucrocodylia) from the Late Cretaceous of Brazil with possible Neosuchian Affinities

 

Titanochampsa iorii 

 Fachini, Godoy, Marsola, Montefeltro & Langer, 2022

 DOI: 10.1080/08912963.2022.2122822 

twitter.com/PaleoLabUSP

Life reconstruction: Júlia d'Oliveira

ResearchGate.net/publication/363926179

ABSTRACT

Most crocodyliforms of the Bauru Group were found in rocks of the Adamantina Formation, whereas the younger Marília Formation is almost devoid of such fossils. Here, we provide a detailed comparative description of MPMA 02–0005/87, a large skull roof found in Marília Formation deposits of the Monte Alto area, assigning it to a new crocodyliform. Despite its fragmentary nature and puzzling suit of characters, the new taxon possesses enough characters to reject its placement within Notosuchia, which is so far the only crocodyliform clade known from the Bauru Group. We tested its phylogenetic position with two data matrices, both of which recovered the new taxon within Neosuchia and Eusuchia. Although the material does not preserve any eusuchian synapomorphy, a neosuchian affinity is supported by: anterior extension of the meatal chamber covered by the squamosal; constricted flange of the posterior process of the postorbital; poorly developed posterolateral process of squamosal. Finally, the large size estimated for the specimen, ranging from 2.98 to 5.88 metres, coupled with its possible neosuchian affinity, suggests a possible semiaquatic behaviour, an ecology rarely explored by the predominantly terrestrial crocodyliforms of the Bauru Group.

 Position of the preserved skull roof of Titanochampsa iorii on a hypothetical crocodyliform skull.

Scale bar = 5 cm.

 Geological map of the Bauru Group in São Paulo state.
The type location of MPMA 02-0005/87 is indicated by a red dot.

CROCODYLOMORPHA Hay, 1930 (sensu Benton and Clark1988)

CROCODYLIFORMES Hay, 1930 (sensu Clark 1986)

MESOEUCROCODYLIA Whetstone and Whybrow 1983

Titanochampsa iorii gen. et sp. nov.

Etymology: The generic name congregates the latinised Greek words ‘titan’ (=large/brutal) and ‘champsa’ (= Titanochampsa ), in reference to the large size of the animal and also its previous identification as a titanosaur dinosaur. The specific epithet ‘iorii’ honours the Brazilian palaeontologist Fabiano V. Iori, due to his numerous contributions to the palaeontology of the Monte Alto region.

Holotype: MPMA 02–0005/87 (Figures 2–5), a partial cranial roof including frontal, parietal, supraoccipital, right postorbital, squamosal, quadrate, quadratojugal, and laterosphenoid. 

   

Thiago S. Fachini, Pedro L. Godoy, Júlio C. A. Marsola, Felipe C. Montefeltro and Max C. Langer. 2022. A Large-sized Mesoeucrocodylian from the Late Cretaceous of Brazil with possible Neosuchian Affinities. Historical Biology: An International Journal of Paleobiology. DOI: 10.1080/08912963.2022.2122822  

  twitter.com/PaleoLabUSP/status/1604102669261578242

ResearchGate.net/publication/363926179_A_large-sized_mesoeucrocodylian_from_the_Late_Cretaceous_of_Brazil