Showing posts with label Crocodylomorpha. Show all posts
Showing posts with label Crocodylomorpha. Show all posts

Sunday, February 15, 2026

[Paleontology • 2026] Galahadosuchus jonesi • A Second Species of non-crocodyliform Crocodylomorph from the Late Triassic fissure deposits of southwestern UK: Implications for locomotory ecological diversity in Saltoposuchidae

 

 Galahadosuchus jonesi 
Bodenham, Spiekman, Maidment, Upchurch & Mannion, 2026

Artwork by M. Dempsey. facebook.com/MEDPalaeo

Abstract
The Late Triassic–Early Jurassic fissures of the Bristol Channel area (southwest England and south Wales) are renowned for their diverse vertebrate faunas. These assemblages have yielded an array of predominantly small-bodied forms that are crucial to our understanding of the early evolution of several major tetrapod clades. Although their dating remains contentious, these deposits provide a valuable insight into biodiversity at a key time in Earth history, given that they span the end-Triassic mass extinction. One of these fissure-fill taxa, Terrestrisuchus gracilis, represents one of the most completely preserved early-branching crocodylomorphs. This species currently occurs exclusively in Late Triassic deposits within the Pant-y-Ffynnon Quarry, whereas only generically indeterminate crocodylomorph remains have been recorded from other fissures in the Bristol Channel area to date. Here we present a detailed anatomical description of a specimen previously assigned to Terrestrisuchus sp. (NHMUK PV R 10002), which comprises the semi-articulated partial postcranial skeleton of a crocodylomorph from the Late Triassic fissure deposits of Cromhall Quarry in the Bristol Channel area. We incorporated NHMUK PV R 10002 into a pre-existing data matrix comprising 39 other operational taxonomic units scored for 138 morphological characters. Phylogenetic analysis under Maximum Parsimony recovers NHMUK PV R 10002 as the sister taxon to Terrestrisuchus, clustering in all cases with the contemporaneous German species Saltoposuchus connectens to form the non-crocodyliform crocodylomorph clade Saltoposuchidae. Under equal and extended implied weights, the Early Jurassic South African species Litargosuchus leptorhynchus and the Late Triassic US species Hesperosuchus agilis, respectively, are additional saltoposuchids. Although NHMUK PV R 10002 exhibits a high degree of morphological similarity to Terrestrisuchus, key differences are evident in the morphology of the dorsal vertebrae, fore- and hindlimb long bones, proximal carpals, metacarpals, and calcaneum. We therefore designate NHMUK PV R 10002 as the holotype of Galahadosuchus jonesi n. gen. n. sp. Several anatomical features indicate that Galahadosuchus was a highly gracile, cursorial terrestrial quadruped with an erect stance, including: elongate proximal carpals; long, slender, and tightly bunched metacarpals; development of a distinct, medially directed femoral head; and a classical crurotarsal ankle joint configuration. A similar stance is also reconstructed for Terrestrisuchus; however, some of the anatomical differences between these two taxa, including the relative proportions and morphology of limb and carpal bones, might correspond to differences in locomotory function, potentially reflecting varying specializations within early-branching crocodylomorphs.

Block A of NHMUK PV R 10002, the holotype of  Galahadosuchus jonesi n. gen. n. sp. 
(a) Photograph of block A in plan view. (b) Line drawing of the elements visible on block A in plan view. Elements visible on the right-hand side of the block (colored hues) are assigned to Galahadosuchus jonesi; elements on the left-hand side of the block (shades of gray) are identified as indeterminate remains of a rhynchocephalian.
as, astragalus; ca, calcaneum; cd, caudal vertebra; ch, chevron; dc, distal carpal; dors, dorsal vertebra; fe, femur; ga, gastralia; ibf, indeterminate bone fragment; is, ischium; mc, metacarpal; mph, manual phalanx; mt, metatarsal; os, osteoderm; pph, pedal phalanx; pu, pubis; ra, radiale; rd, radius; ti, tibia; ul, ulna; ulr, ulnare. Scale bar represents 100 mm.

Archosauria Cope, 1869–1870 (sensu Gauthier & Padian, 2020).
Crocodylomorpha (Hay, 1930, sensu Nesbitt, 2011).
Saltoposuchidae (Crush, 1984, sensu Spiekman, 2023).

Galahadosuchus gen. nov.

Etymology. Galahad” from Arthurian legend, a knight renowned for his moral uprightness; combined with “suchus” from the Greek for crocodile. The genus name alludes to the upright posture of the taxon, playing on the dual sense of “upright” as both moral and physical.
 
Galahadosuchus jonesi, sp. nov.

Etymology. The species epithet honors David Rhys Jones, a teacher at Ysgol Uwchradd Aberteifi, in recognition of his work inspiring students at the school (including EHB) to pursue their passion for science.

Life reconstruction of Galahadosuchus jonesi n. gen. n. sp.
 The morphology of regions of the body that are not currently known for Galahadosuchus jonesi (i.e., not preserved in NHMUK PV R 10002) is inferred from comparison with Terrestrisuchus gracilis (Spiekman et al., 2023, 2024) due to the high degree of morphological similarity between these two taxa. Scale bar represents 100 mm.
Artwork by M. Dempsey. facebook.com/MEDPalaeo



Ewan H. Bodenham, Stephan N. F. Spiekman, Susannah C. R. Maidment, Paul Upchurch, Philip D. Mannion. 2026. A Second Species of non-crocodyliform Crocodylomorph from the Late Triassic fissure deposits of southwestern UK: Implications for locomotory ecological diversity in Saltoposuchidae. The Anatomical Record. DOI: doi.org/10.1002/ar.70162 [12 February 2026]


Thursday, August 28, 2025

[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
  

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]
 

Thursday, March 20, 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


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 

 
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

Monday, September 23, 2024

[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.   
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
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

Wednesday, August 14, 2024

[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
 
 
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  

Monday, August 5, 2024

[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. 

 
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 

Monday, June 17, 2024

[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


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

Friday, February 2, 2024

[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


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


Wednesday, January 10, 2024

[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


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 formVaranosuchus 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

วาราโนซูคัส สกลนครเอนซิส  🐊🐊
จระเข้ทรงเหี้ย จระเข้ดึกดำบรรพ์ชนิดใหม่ชนิดที่ 12 ของประเทศไทย  
 จากหมวดหินเสาขัว ต้นยุคครีเทเชียส จ.สกลนคร 


Tuesday, October 17, 2023

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


Macrospondylus bollensis  Jäger, 1828

in Johnson, Amson & Maxwell, 2023.

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

Tuesday, January 24, 2023

[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

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