[Paleontology • 2026] Austronaga minuta • Highly aquatic marine stem Archosaur with soft tissue preservation

Austronaga minuta Wang, Lei & Li, 2023

 

in Wang, Fraser, Spiekman, Z. Li, et C. Li, 2026. 

DOI: doi.org/10.1126/sciadv.aeb7528 

Artwork by Gabriel Ugueto

 

Abstract

Archosauromorpha is a dominant reptile clade that primarily occupied terrestrial ecosystems with limited secondarily aquatic invasions that are poorly known. Here we report on a well-preserved Triassic reptile representing the earliest stem-archosaur to evolve unequivocal aquatic specializations. This taxon exhibits a suite of aquatic adaptations previously unknown in stem-archosaurs, such as hyperphalangy, enhanced paddle-like forelimbs, and a loss of articulation between the sacrum and pelvis, indicating an advanced aquatic lifestyle. The fossil exhibits the oldest known stomach, liver, and intestinal preservations in reptiles. Our findings provide unexpected insights into the early aquatic diversification of Archosauromorpha during the Triassic marine ecosystem recovery and highlight a conservative gastrointestinal system in an early Mesozoic vertebrate. In the absence of clear terrestrial members of the other major Mesozoic marine reptile lineages (e.g., ichthyosaurs and sauropterygians), this discovery provides an unambiguous example of such a lineage including both decidedly terrestrial and extensively marine forms, providing tantalizing evidence for the land-to-sea transition in Triassic reptiles.

Systematic paleontology

Diapsida, Osborn, 1903.

Archosauromorpha, von Huene, 1946.

Tanysauria, Spiekman et al., 2024.

Trachelosauridae, Abel 1919 (sensu Spiekman et al., 2024).

Skeleton of the holotype of Austronaga minuta (IVPP V18579). Abbreviations are in the Supplementary Materials. Scale bars, 2 cm (A) and 1 cm (B to D).

Austronaga minuta, Wang et al., 2023.

Type specimen: Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) V18579, a complete articulated skeleton preserved on two slabs (Fig. 1).

Locality and horizon: Waina Village, Luoping County, Yunnan Province, China; Member II of Guanling Formation, middle Anisian (Pelsonian), Middle Triassic.

Emended diagnosis: A tanysaur with the following features: quadrate anteroposteriorly broad and plate-like in lateral view with concave posterior margin; 18 cervical, 24 dorsal vertebrae; tall axe-shaped neural spine on axis; cervical neural spines prominent, with convex dorsal margin and without anterodorsal or posterodorsal projections; chevrons of mid-caudal region hatchet-shaped, with prominent distal expansion and a notch at the midpoint of its ventral margin; forelimb distinctly longer than hindlimb with humerus to femur length ratio over two; hyperphalangy present in both manus and pes.

Reconstruction of the long-necked marine reptile Austronaga minuta.

Artwork by Gabriel Ugueto

Wei Wang, Nicholas C. Fraser, Stephan N. F. Spiekman, Zhiheng Li, Olivier Rieppel, Hong Lei, Torsten M. Scheyer and Chun Li. 2026. Highly aquatic marine stem Archosaur with soft tissue preservation. Science Advances. 12(31); DOI: doi.org/10.1126/sciadv.aeb7528 [29 Jul 2026]

[Paleontology • 2024] Cranial Osteology and Paleoneurology of Tarjadia ruthae: An erpetosuchid pseudosuchian from the Triassic Chañares Formation (late Ladinian-?early Carnian) of Argentina

 

Tarjadia ruthae Arcucci & Marsicano, 1998
 

in Desojo, von Baczko, Ezcurra, Fiorelli, Martinelli, ... et Lacerda, 2026. 

DOI: doi.org/10.1002/ar.25382 

Reconstruction: Jorge Blanco

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Abstract

Tarjadia ruthae is a quadrupedal terrestrial pseudosuchian from the Middle-early Upper Triassic of the Chañares Formation, La Rioja Province, Argentina. Originally, this species was identified as an indeterminate archosaur and later as a doswelliid archosauriform based on very fragmentary specimens characterized by the ornamentation of the skull roof and osteoderms. Additional specimens (including skulls and postcrania) recovered in the last decade show that Tarjadia is an erpetosuchid, an enigmatic pseudosuchian group composed of six species registered in Middle-Upper Triassic continental units of Tanzania, Germany, Scotland, North America, Brazil, and Argentina. Tarjadia ruthae from Argentina and Parringtonia gracilis from Tanzania are the best preserved and more abundant species. Although the monophyly of Erpetosuchidae is well supported, alternative high-level positions within Archosauria have been suggested, such as sister taxon to Crocodylomorpha, Aetosauria, or Ornithosuchidae. In order to improve the knowledge about the erpetosuchids, we performed a detailed description and paleoneurological reconstruction of the skull of Tarjadia ruthae, based on two articulated partial skulls (CRILAR-Pv 478 and CRILAR-Pv 495) and other fragmentary specimens. We analyzed the stratigraphic and geographic occurrence of historical and new specimens of Tarjadia and provided a new emended diagnosis (the same for the genus as for the species, due to monotypy) along with a comparative description of the cranial endocast. The skull of Tarjadia is robust, with a thick and strongly ornamented skull roof, triangular in dorsal view, with concave lateral margins at mid-length that form an abrupt widened posterior region. The external nares are the smallest openings of the skull. The antorbital fossa is deeply excavated and has a small heart-shaped fenestra with both lobes pointing anteriorly. The supratemporal fenestrae are as large and rounded as the orbits, and the infratemporal fenestrae are L-shaped with an extensive excavation along the jugal, quadratojugal and quadrate. The hemimandibles are low, slightly concave on the dentigerous region and strongly convex on the posterior region, conferring them a S-shaped profile in dorsal view. The external mandibular fenestra is small and elliptic, being twice longer than high. The maxillary dentition is restricted to the anterior to mid region of the rostrum. Since the braincase of both specimens is partially damaged, the dorsal surface of the brain could not be entirely reconstructed. As a result, the endocast is anteroposteriorly elongated and seemingly flat, and the cephalic flexure seems to be lower than expected for a suchian. The labyrinth is twice wider than high, the semicircular canals are remarkably straight, and the anterior canal is longer than the posterior one.

Keywords: anatomy, Archosauria, Erpetosuchidae, neuroanatomy, skull

Systematic paleontology

Archosauriformes Gauthier et al., 1988.

Archosauria Cope, 1869 sensu Gauthier & Padian, 1985.

Pseudosuchia von Zittel, 1887–1890 sensu Gauthier & Padian, 1985.

Erpetosuchidae Watson, 1917 sensu Nesbitt & Butler, 2013.

Tarjadia ruthae Arcucci & Marsicano, 1998

Life reconstruction of Tarjadia ruthae by Jorge Blanco.

J. B. Desojo, M. B. von Baczko, M. D. Ezcurra, L. E. Fiorelli, A. G. Martinelli, P. Bona, M. J. Trotteyn and M. Lacerda. 2024. Cranial Osteology and Paleoneurology of Tarjadia ruthae: An erpetosuchid pseudosuchian from the Triassic Chañares Formation (late Ladinian-?early Carnian) of Argentina. The Anatomical Record. DOI: doi.org/10.1002/ar.25382 [23 January 2024]

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[Paleontology • 2026] Antusuchus rionegrinus • A New early peirosaurid terrestrial Crocodile (Notosuchia: Peirosauridae) from La Buitrera (Candeleros Formation), Río Negro, Argentina

Antusuchus rionegrinus 

Fernández-Dumont, Apesteguía, Pol, Bona, Pérez Mayoral & Vega, 2026

 

DOI: doi.org/10.1080/08912963.2026.2683112  

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ABSTRACT

Notosuchia represents one of the most morphologically diverse groups of Mesozoic crocodyliforms and was particularly abundant in the Cretaceous of Gondwana. Among them, Peirosauridae comprises medium-sized terrestrial predators widely distributed across southern continents during the Late Cretaceous. Here we describe a new peirosaurid crocodyliform, Antusuchus rionegrinus gen. et sp. nov., from the Cenomanian Candeleros Formation of the Neuquén Basin (Río Negro Province, Argentina). The material, recovered from the La Buitrera Palaeontological Area, includes cranial and postcranial remains. Micro-computed tomography and anatomical comparisons reveal a unique combination of characters, including a short rostrum, an elongated palatal depression adjacent to the maxillary tooth row, a rod-shaped jugal bar, and a prominent sagittal crest. The dentition is ziphodont and includes a hypertrophied third maxillary tooth, consistent with predatory habits. Phylogenetic analyses recover Antusuchus rionegrinus as the earliest-branching member of Peirosauridae, sister to all remaining peirosaurids. This discovery provides new insights into the early evolution of peirosaurids and highlights the importance of the La Buitrera fauna for understanding mid-Cretaceous terrestrial ecosystems and the diversification of notosuchian crocodyliforms.

KEYWORDS: Peirosauridae, La Buitrera, Cretaceous, Notosuchia, Candeleros Formation, Neuquén Basin

Systematic Palaeontology

Crocodyliformes Hay, 1930

Notosuchia Gasparini, 1971 [Ruiz et al., 2021]

Peirosauria Leardi et al., 2024

Peirosauridae Gasparini, 1982 [Leardi et al., 2024]

Antusuchus rionegrinus gen. et sp. nov.

 

Etymology: Antu means sun in the Mapudungún language. Suchus is Latinised from Greek Souchos in references to the Egyptian crocodile-headed god Sebek. Rionegrinus named after Río Negro Province.

Holotype: MPCA PV 1294 (Figures 37), articulated skull and jaws.

 

Geographical and geological proceeding: The material was found in rocks representing the last 50 m of the Candeleros Formation deposit, at the base of the levels containing the La Buitrera fauna. The site corresponds to the base of the ‘Cañadón de Las Tortugas’ site, within the La Buitrera locality, one of the localities of the LBPA.

Diagnosis: A notosuchian crocodyliform characterised by the following unique combination of characters (autapomorphies indicated with asterisk): third premaxillary tooth larger than the fourth; large elongated depression close to the medial margin of the mid maxillary toothrow*; rostrum shorter than 50% of the total skull length; maxillary contribution to antorbital fossa as dorsoventrally high as the maxillary lateral surface between antorbital fossa and alveolar margin and extending posteriorly up to the posterior end of the antorbital fossa*; antorbital fossa restricted to posteroventral corner of antorbital fenestra; lacrimal extensively sutured to jugal; subtriangular ...

  

María Lucila Fernández-Dumont, Sebastián Apesteguía, Diego Pol, Paula Bona, Joaquín Pérez Mayoral and Nahuel Vega. 2026. A New early peirosaurid terrestrial Crocodile (Notosuchia) from La Buitrera (Candeleros Formation), Río Negro, Argentina. Historical Biology: An International Journal of Paleobiology. DOI: doi.org/10.1080/08912963.2026.2683112 [23 Jun 2026]

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[Paleontology • 2026] Silescelida acristata • A New eucrocopodan Archosauriform from the Middle Triassic of southern Brazil and the Phylogeny of Euparkeriidae

Silescelida acristata 

Garcia, Cerqueira, Battista,  Andrade & Müller, 2026

DOI: doi.org/10.1038/s41598-026-53740-9 

life reconstruction by Matheus Fernandes Gadelha. 

Abstract

Archosauriformes comprise a diverse range of reptiles, including the crown-group Archosauria, which flourished during the Triassic Period. Early-diverging archosauriforms, such as proterosuchids and erythrosuchids, are becoming progressively well-known due to recent studies and consistently resolve at the base of the clade. More crownward, Eucrocopoda includes archosauriform taxa that increasingly approximate the ancestral archosaur body plan. Early-diverging eucrocopodan archosauriforms have a widespread paleogeographic record but remain poorly understood in terms of ingroup relationships. Within this radiation, Euparkeriidae is particularly challenging, because its ingroup composition and monophyly is debated, with some authors supporting a non-monospecific Euparkeriidae, whereas others fail to recover this hypothesis. The eponymous Euparkeria capensis is known from the Early to Middle Triassic of South Africa, whereas other putative euparkeriids are primarily known from the Early to Middle Triassic of China, Germany, Poland, and Russia. Here, we describe a new early-diverging eucrocopodan (Silescelida acristata gen. et sp. nov.) from the Middle Triassic of southern Brazil. Phylogenetic analyses incorporating this taxon suggest a possible placement within Euparkeriidae, though its position shows instability depending on the operational taxonomic units considered, especially among other putative euparkeriids. This discovery not only informs on the temporal and paleogeographic distribution of euparkeriids but also sheds light on the origin and early evolution of eucrocopodans, representing the first record of this archosauriform grade in the Triassic of Brazil. More broadly, the new taxon underscores the significance of South American Triassic deposits within the evolutionary history of archosauriforms.

Archosauromorpha von Huene, 1946 sensu Gauthier, 2020

Archosauriformes Gauthier et al., 1988 sensu Gauthier, 2020 

Eucrocopoda Ezcurra, 2016

cf. Euparkeriidae von Huene, 1920 sensu Sookias and Butler, 2013

Provenance and material of Silescelida acristata gen. et sp. nov.
 (A) Map of the Posto site and the surface distribution of the geologic units in the area. (B) General view of the Posto site. (C) Studied specimen MCP 4186-PV (holotype of Silescelida acristata gen. et sp. nov.) showing association between its elements prior to mechanical preparation.
(D) Silhouette and preserved skeletal elements (not to scale) of Silescelida acristata gen. et sp. nov. (ilium reversed).

Abbreviations: fe, femur; il, ilium; sc, scapula. Silhouette and life reconstruction of Silescelida acristata gen. et sp. nov. by Matheus Fernandes Gadelha. Map was generated with GIMP 3.0 (gimp.org) based on the geological map of Rio Grande do Sul (https://rigeo.sgb.gov.br/bitstream/doc/10301/2/Geologico_MDT.pdf).

Silescelida acristata gen. et sp. nov.  

Holotype. MCP 4186-PV, a left scapula, a right ilium, and a left femur (Fig. 1C, D). The elements were found in association (attached to each other) and are size-compatible; therefore, they are considered to belong to the same individual.

Type locality, age, and horizon. Posto (or Posto de Gasolina; Fogliarini) site (29°37’38.9”S 53°22’06.5”W), municipality of Dona Francisca, Rio Grande do Sul, Brazil (Fig. 1A, B). Dinodontosaurus AZ of the Pinheiros-Chiniquá Sequence of the Santa Maria Supersequence, Paraná Basin51,52. It is considered Ladinian in age30,35,53,54,55,56,57,58.

Diagnosis. The holotype of Silescelida acristata differs from all other known non-archosaurian archosauriforms in the following combination of traits: scapular blade without an anteroposterior constriction at its base; asymmetrical expansion of the scapular blade at its dorsal portion; straight posterior margin of the scapular blade, forming a right angle with the dorsal margin of the glenoid; elliptical tuber for the m. triceps dorsal to the glenoid; dorsal margin of the dorsal iliac blade straight in dorsal and lateral views; dorsal iliac blade as deep as the acetabulum; notch between the ischiadic peduncle and the ventral apex of the medial acetabular wall; medially expanded femoral head; absence of a longitudinal groove on the proximal surface of the femoral head; posteromedial tuber as the only well-developed tuber on the femoral head; absence of an elevated mound or crest-like structure as the attachment site for the m. caudofemoralis (local autapomorphy); extensor fossa on the anterior surface of the femoral distal end; distal femoral condyles with the same degree of ventral development (not uneven).

Etymology. The generic name combines the Latin siles (“silence”) and the Greek skelēs (“hind leg”), referencing the loss of the proximal femur bearing the specimen’s collection code, which obscured its provenance until its recent rediscovery. The specific epithet derives from the Latin prefix a- (“without”) and cristāta (“crested”), referring to the absence of a crest or flange attachment site for the m. caudofemoralis (= fourth trochanter), a diagnostic feature of the taxon.

Silescelida acristata gen. et sp. nov. life reconstruction.

 Artwork by Matheus Fernandes Gadelha. 

Biogeography of early-diverging eucrocopodans and paleoart depicting Silescelida acristata gen. et sp. nov. in life.
 (A) Triassic world map depicting the paleogeographic distribution of early-diverging eucrocopods. Classification is based on the phylogenetic analyses in this contribution. Silhouettes (not to scale) based on the skeletal reconstruction of Euparkeria capensis by Demuth et al.83. Dorosuchus neoetus is based on the type-series and Osmolskina czatkowicensis is based on the holotype.
(B) Silescelida acristata gen. et sp. nov. life reconstruction. Artwork by Matheus Fernandes Gadelha. Map was generated with GIMP 3.0 (gimp.org) based on The Paleobiology Database (paleobiodb.org).

 

Maurício S. Garcia, Gabriela M. Cerqueira, Francesco Battista, Marco B. de Andrade and Rodrigo T. Müller. 2026. A New eucrocopodan Archosauriform from the Middle Triassic of southern Brazil and the Phylogeny of Euparkeriidae. Scientific Reports. 16: 16585. DOI: doi.org/10.1038/s41598-026-53740-9  [10 June 2026]

 

[Paleontology • 2026] Carinthiasuchus kandutschi • A New Archosaur (Reptilia: Diapsida) from the Triassic of Austria

 

Carinthiasuchus kandutschi 

 Vecchia & Cau, 2026 

DOI: doi.org/10.54103/2039-4942/29890

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Abstract 

A partial skeleton of a small reptile with a distinctive maxilla, dentition, caudal vertebrae and osteoderms from the marine Partnach Formation (Ladinian-earliest Carnian) near Jadersdorf (Gitschtal, Hermagor) in the Gailtal Alps of Carinthia (Austria), represents a new archosaur taxon Carinthiasuchus kandutschi gen. n. sp. n.. It is diagnosed by autapomorphies in the anterior process and subnarial foramen of the maxilla, accessory articular processes in the neural arches of mid-distal caudal vertebrae, and shape and arrangement of the caudal osteoderms. It also shows a unique combination of features regarding the extent of the antorbital fossa in the maxilla and the morphology of its ventral edge, dentary shape, dentition, caudal vertebrae elongation and morphology. A segment of 16 mid-distal caudal vertebrae is one of the better articulated tail segments ever found in Triassic archosaurs, showing the arrangement of the dorsal osteoderms and the presence of accessory processes in the neural arches stiffening the posterior termination of the tail. Phylogenetic analysis recovered Carinthiasuchus kandutschi as a pseudosuchian in a basal position within the Poposauroidea. Absence of swimming adaptation in the tail and the presence of terrestrial plant remains in the same outcrop suggest terrestrial habits for this archosaur reptile.

Carinthiasuchus kandutschi, gen. n. sp. n., Nockalm7030u, holotype. Scale bar equals 100 mm.

Carinthiasuchus kandutschi, gen. n. sp. n., Nockalm7030u, ho-lotype, skull and mandible. (A) Photograph, (B) drawing (bone is gray and teeth darker gray).

Abbreviations: d, den-tary; f, frontal; j, jugal; la, lacrimal; mx, maxilla; n, nasal; pt, pterygoid; q, quadrate; snf, subnarial foramen; sq, squamo-sal; th, tooth; v, vomer; *, left element.

Legenda: 1 = actual margin of the bone; 2 = broken margin of the bone; 3 = margin of the impression of the bone; 4 = probable margin of the skeletal element; 5 = broken surface of the skeletal element. Scale bar is 10 mm.

Reptilia Laurenti, 1768 sensu Modesto & Anderson, 2004

Diapsida Osborn, 1903 

Archosauromorpha von Huene, 1946 sensu Dilkes, 1998

Archosauriformes Gauthier, Kluge & Rowe,1988

Archosauria Cope, 1869

Pseudosuchia Zittel, 1887-1890

Suchia Krebs, 1974 (sensu Nesbitt, 2011)

Paracrocodylomorpha Parrish, 1993

Poposauroidea Nopcsa, 1923

Carinthiasuchus kandutschi gen. n. sp. n.

Holotype: Nockalm7030u, part of the skull including the right maxilla with two teeth, part of the two mandibular rami, and parts of the mid-distal portion of the tail with osteoderms (Fig. 3).

Locality and stratigraphic horizon: Southern flank of Mt. Großboden NE of Jadersdorf in the Gitschtal close to Hermagor, Carinthia, SE Austria. Partnach-Schichten/Fellbach Kalk, Ladinian-lo-wermost Carnian.

Diagnosis. Carinthiasuchus kandutschi gen. n. sp. n. is an archosaur (see discussion) with the following apomorphies: short, straight and pointed anterior process of the maxilla with a dorsal articular facet and bordering dorsally a comparatively large subnarial foramen; accessory articular processes of the neural arches in the last middle and in the distal caudal vertebrae; paired and symmetrical paramedian osteoderms above the proximal mid-caudal vertebrae, drop-shaped, with coarse denticles along the margins posteriorly, with longitudinal median ridge dorsally but without sculpturing; single median row of elongated and lying 8-shaped osteoderms in the following mid-distal caudals with three osteoderms per vertebra, one above the middle of the vertebra and half on the anterior and ...

Etymology: The genus is named after Carinthia, the Latin name of Kärnten, the southernmost federate state of Austria where the specimen was discovered and the Greek term soúkhos (σούχος) for crocodile. The species name is inhonourof the discoverer of the holotype, Georg Kandutsch (Arriach/Hinterwinkl, Austria).

FABIO MARCO DALLA VECCHIA and ANDREA CAU. 2026. Carinthiasuchus kandutschi, A NEW ARCHOSAUR (REPTILIA: DIAPSIDA) from the Triassic of AUSTRIA. RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA. 132(2); DOI: doi.org/10.54103/2039-4942/29890 [08-06-2026]

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[Paleontology • 2026] Labrujasuchus expectatus • A New shuvosaurid (Archosauria: Poposauroidea) from the Late Triassic (Norian) Hayden Quarry of New Mexico, U.S.A.

Labrujasuchus expectatus

Turner, Kernan, Laing, Pritchard, Stocker, Irmis, Smith, Werning & Nesbitt, 2026

DOI: doi.org/10.1080/02724634.2026.2618182

Artwork: Jorge Gonzalez/NHMLAC Dinosaur Institute

ABSTRACT

Bipedal shuvosaurid archosaurs were present for much of the Late Triassic Period. The clade is particularly diverse in Upper Triassic assemblages in the western U.S.A. Isolated bones are easily differentiated from contemporary archosaurs, but the two named North American species, Shuvosaurus inexpectatus and Effigia okeeffeae, display remarkably similar skeletons. Here we describe a new shuvosaurid species, Labrujasuchus expectatus, gen. et sp. nov., from the middle Norian (∼212 Ma) Hayden Quarry of northern New Mexico, U.S.A., located within the Petrified Forest Member of the Chinle Formation, that fills the temporal gap between the two species. The holotype consists of a partial skeleton, with additional shuvosaurid material from the Hayden Quarry likely pertaining to this taxon. This taxon is distinguished by four autapomorphies and assignable to Shuvosauridae based on a deep fossa present on the posterodorsal edge of the coracoid, the proximal portion of the humerus less than twice the width of the midshaft, the anteromedial tuber of the femur large and ‘hooked’ posteriorly, and a ventrally descended posterolateral portion of the femoral head. Recent Bayesian estimates of archosaur phylogeny and divergence times suggested a Middle Triassic split for Shuvosauridae as well as a decrease in the rate of morphological evolution for the clade relative to that of other archosaurs. The anatomical similarity of L. expectatus with other shuvosaurids is consistent with these estimated low rates, and the long gaps in the fossil record for the clade suggest that much of their evolutionary history remains to be sampled.

Reconstruction of Labrujasuchus expectatus, a new species of Shuvosauridae from Late Triassic rocks of Ghost Ranch, New Mexico.

Artwork: Jorge Gonzalez/NHMLAC Dinosaur Institute

SYSTEMATIC PALEONTOLOGY

ARCHOSAURIA Cope, 1870 (sensu Gauthier & Padian, 1985)

SUCHIA Krebs, 1974 (sensu Benton & Clark 1988)

SHUVOSAURIDAE Chatterjee, 1993 (sensu Nesbitt, 2011)

LABRUJASUCHUS gen. nov.

Type Species—Labrujasuchus expectatus

Etymology—The generic name Labrujasuchus (“la-broo-ha-soo-kus”) is derived from “Ranchos de los Brujos,” Ranch of the Witches, an old Spanish name for the Ghost Ranch area, and the Greek word Σοῦχος (suchus) meaning “crocodile.” It is masculine in gender.

 

LABRUJASUCHUS EXPECTATUS sp. nov.

Etymology—From the Latin “expectatus” for expected or awaited.

The species name is based on the anticipated nature of a shuvosaurid discovery at the Hayden Quarry.

Alan H. Turner, Ciara E. Kernan, Adam Laing, Adam C. Pritchard, Michelle R. Stocker, Randall B. Irmis, Nathan D. Smith, Sarah Werning and Sterling J. Nesbitt. 2026. A New shuvosaurid (Archosauria, Poposauroidea) from the Late Triassic (Norian) Hayden Quarry of New Mexico, U.S.A. Journal of Vertebrate Paleontology.  e2618182 DOI: doi.org/10.1080/02724634.2026.2618182  [26 May 2026]

[Paleontology • 2026] Eosphorosuchus lacrimosa • A Short-snouted ‘sphenosuchian’ with unusual Feeding Anatomy demonstrates that Ecological Specialization occurred early in Crocodylomorph Evolution

 

Eosphorosuchus lacrimosa

Margulis-Ohnuma, Ruebenstahl, Meyer & Bhullar, 2026

 

DOI: doi.org/10.1098/rspb.2026.0130 

Art by Julio Lacerda

Abstract

The early evolution and diversification of Crocodylomorpha is a key component of vertebrate evolution on land but is somewhat poorly understood as a result of limited data. We describe Eosphorosuchus lacrimosa gen. et sp. nov., an early crocodylomorph from the Late Triassic of Ghost Ranch, New Mexico, whose cranial anatomy is divergent from that of other early crocodylomorphs (including Hesperosuchus agilis, to which it had been tentatively assigned), featuring an unusually short and osteologically reinforced facial region. A robust upper temporal arch and prominent surangular ridge indicate the presence of well-developed superficial external adductor musculature, which is divergent relative to pseudosuchians generally. These autapomorphies suggest specialization for a powerful bite. Bayesian and maximum parsimony phylogenetic analyses find E. lacrimosa outside of an H. agilis clade, near the base of Crocodylomorpha. The specializations of E. lacrimosa therefore represent the beginnings of ecological diversification within Crocodylomorpha among animals of a similar size, predating the Late Triassic appearance of Crocodyliformes and the Jurassic radiation of mesoeucrocodylians. Coexistence in the same single-event death assemblage of E. lacrimosa and H. agilis—two small early crocodylomorphs with functionally significant anatomical differences—suggests partitioning of terrestrial carnivorous niches within the ‘sphenosuchian’ grade.

Keywords: Crocodylomorpha, Sphenosuchia, Triassic, Hesperosuchus agilis, phylogenetics

Photographs and line drawings of the skull of Eosphorosuchus lacrimosa as preserved and prepared in right ventrolateral view (a, c) and left dorsolateral view (b, d). Grey shading represents matrix or bones of other individuals; halftone represents areas of breakage.

Abbreviations: an, angular; e, ectopterygoid; f, frontal; j, jugal; l, lacrimal; m, maxilla; n, nasal; pa, prearticular; pb, palpebral; pl, palatine; pm, premaxilla; po, postorbital; pt, pterygoid; sa, surangular; tpt, transverse process of the pterygoid. Scale bar is 2 cm.

 

ARCHOSAURIA Cope, 1869 (Gauthier & Padian [2020])

PSEUDOSUCHIA Zittel, 1887 

CROCODYLOMORPHA Hay, 1930 (emend. Walker [1970])

Eosphorosuchus lacrimosa gen. et sp. nov.

 

 Etymology: Eosphorosuchus derives from ‘Eosphoros,’ one of two Greek gods representing the planet Venus and the counterpart of Hesperos. As Eosphoros was the ‘dawn-bringer’, this name highlights both the dawning of crocodylomorph ecological diversity and the close historic association of this specimen with the genus Hesperosuchus. ‘Suchus’ derives from ‘soukhos’, Greek for crocodile. The specific epithet lacrimosa refers to the distinctive lacrimal region.

 

Miranda Margulis-Ohnuma; Alexander A. Ruebenstahl; Dalton L. Meyer and Bhart-Anjan S. Bhullar. 2026. A Short-snouted ‘sphenosuchian’ with unusual Feeding Anatomy demonstrates that Ecological Specialization occurred early in Crocodylomorph Evolution. Proc Biol Sci . 293 (2069): 20260130. DOI: doi.org/10.1098/rspb.2026.0130 [15 Apr 2026]

[Paleontology • 2026] Crocodylus lucivenator • Lucy’s peril: A Pliocene crocodile from the Hadar Formation, north-eastern Ethiopia

  

Crocodylus lucivenator

 Brochu, Drumheller, Campisano, Tekle, Getachew, Head, Platt & Leaphart, 2026

 

DOI: doi.org/10.1080/14772019.2026.2614954 

Artwork by Tyler Stone

Abstract

We herein describe a new crocodile, Crocodylus lucivenator sp. nov., from palaeoanthropological sites in the Pliocene Hadar Formation in north-eastern Ethiopia. It shares derived features and plesiomorphic states with two Pleistocene species of Crocodylus from East Africa. Conversely, C. lucivenator bears a midline boss on the dorsal surface of the rostrum similar to those of modern Neotropical crocodiles and late Miocene crocodiles from Libya and Kenya. A boss is also present on Pliocene specimens from Kanapoi in Kenya previously referred to C. thorbjarnarsoni. Some C. lucivenator also have a more substantial prenarial rostrum than other Palaeoafrican Crocodylus, though not to the same extent as in extant Crocodylus, and its expression is variable. Phylogenetic analysis supports a close relationship between C. lucivenator, Kanapoi Crocodylus, C. anthropophagus, C. thorbjarnarsoni, and fossils from the Turkana Basin previously misreferred to C. checchiai. A close relationship with Neoafrican Crocodylus is rejected, reinforcing a comparatively recent arrival for Neoafrican Crocodylus in East Africa. Crocodylus lucivenator and the Kanapoi form are very similar, but an exclusive relationship is not unambiguously supported in our analysis. The phylogenetic placement of the Palaeoafrican clade depends on how one regards the prenarial rostrum, and positions outside crown Crocodylus or close to the Neotropical clade can be equally optimal. One mandible preserves pathological structures consistent with injuries sustained during intraspecific combat. Crocodylus lucivenator appears to have been the only crocodylian in the Hadar Formation, while coeval deposits in the Turkana Basin preserve as many as four species. The reason for this disparity is unclear.

 

Keywords: Crocodylus lucivenator, Hadar Formation, Pliocene, prenarial rostrum, cladistic assessment, Turkana Basin

Crocodylus lucivenator sp. nov.

Etymology. luci-, Latin for light, but here used with reference to A.L. 288-1 (Lucy), the iconic Australopithecus afarensis skeleton from Hadar; -venator, Latin, hunter. There is no evidence A.L. 288-1 was ever attacked by a crocodile, but her species (and most likely Lucy herself) would doubtless have been pursued as prey by this species.

Christopher A. Brochu, Stephanie K. Drumheller, Christopher Campisano, Getahun Tekle, Tomas Getachew, Jason J. Head, Nathan C. Platt & Daniel Leaphart. 2026. Lucy’s peril: A Pliocene crocodile from the Hadar Formation, north-eastern Ethiopia. Journal of Systematic Palaeontology. 24(1); 2614954. DOI: doi.org/10.1080/14772019.2026.2614954 [11 Mar 2026]

[Paleontology • 2026] Sonselasuchus cedrus • Osteology and Relationships of A New shuvosaurid (Pseudosuchia: Poposauroidea: Shuvosauridae) from the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona, U.S.A

Sonselasuchus cedrus

Smith & Sidor, 2026

DOI: doi.org/10.1080/02724634.2025.2604859

Artwork by Gabriel Ugueto

ABSTRACT

Shuvosauridae is a clade of pseudosuchian archosaurs currently represented by three named species characterized by a body plan strikingly convergent with that of ornithomimid theropod dinosaurs. This paper documents a new genus and species of shuvosaurid from the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona. Sonselasuchus cedrus, gen. et sp. nov., is largely diagnosed by features of the maxilla, including a reduced body and anterior process, an enlarged subnarial foramen, and an expanded facet on the posterior process, although other unique cranial features are also noted herein. By contrast, its postcranial anatomy is largely similar to what has been described for other shuvosaurids, although subtle differences are noted. A phylogenetic analysis finds S. cedrus in an unresolved clade with Effigia okeeffeae and Shuvosaurus inexpectatus, likely as a result of non-overlapping missing data, particularly for the skull of Shuvosaurus. A review of the shuvosaurid fossil record indicates that shuvosaurids were persistent components of Late Triassic terrestrial vertebrate faunas in North America. S. cedrus is represented by a minimum number of 36 individuals, mostly skeletally immature, that occur within a multitaxic bonebed of almost exclusively disarticulated elements. An analysis of the relative size change of limb dimensions indicates the forelimb was growing on a negative allometric trajectory relative to the hindlimb, which is consistent with a transition in locomotory mode from quadrupedal to bipedal in S. cedrus during ontogeny.

Life restoration of Sonselasuchus cedrus as depicted by Gabriel Ugueto. Note the occurrence of individuals in both bipedal and quadrupedal stances.

SYSTEMATIC PALEONTOLOGY

ARCHOSAURIA Cope, 1869

PSEUDOSUCHIA Zittel, 1887–1890

PARACROCODYLOMORPHA Parrish, 1993

POPOSAUROIDEA Nopcsa, 1923

SHUVOSAURIDAE Chatterjee, 1993

SONSELASUCHUS CEDRUS gen. et sp. nov.

Etymology—For the genus, ‘Sonsela’ refers to the Sonsela Member of the Chinle Formation, the type section is located at the Sonsela Buttes on the Navajo Nation; ‘suchus’ is a Latinization of the Greek word soukhos, for the Egyptian crocodile deity Sobek, reflecting the pseudosuchian affinities of the taxon. The specific epithet, ‘cedrus’ is the genus name for the common cedar (actually the juniper, Juniperus spp.) and refers to Cedar Tank, the geographic feature in Petrified Forest National Park near the type locality.

Holotype—PEFO 47305/UWBM 119436, left maxilla.

Locality and Horizon—The Kaye Quarry (PFV 410/UWBM C2226) is located west of Cedar Tank at Petrified Forest National Park, Apache County, Arizona, U.S.A. (Fig. 1). The site is within the Jim Camp Wash beds of the Sonsela Member of the Chinle Formation and is Norian in age (Marsh et al., 2024). ...

Elliott Armour Smith and Christian A. Sidor. 2026. Osteology and Relationships of A New shuvosaurid (Pseudosuchia, Poposauroidea) from the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona, U.S.A. Journal of Vertebrate Paleontology. e2604859. DOI: doi.org/10.1080/02724634.2025.2604859 [08 Mar 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

DOI: doi.org/10.1002/ar.70162

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]

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