[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 • 2026] Climate-extreme-driven Genesis of A Cretaceous Dinosaur Lagerstätte

 

 in Fanti, Consorti, Muscioni, Baldassari, Dinelli, Polentarutti, ... et Chiarenza. 2026. 

DOI: doi.org/10.1016/j.gloplacha.2026.105589 

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Artwork by palaeoartist Davide Bonadonna

Highlights: 

• Monsoon-driven storms created a Cretaceous dinosaur Lagerstätte.

• Tidal microcouplets yield an unprecedented ∼40-year chronometry.

• Synchrotron micro-XRF/XRD maps refute seasonal varve interpretation.

• Microbial mats enabled rapid sealing and exceptional soft-tissue preservation.

• New genetic model and toolkit for climate event-driven preservation in carbonates.

Abstract

Konservat-Lagerstätten provide exceptional records of past ecosystems, yet the environmental and climatic processes governing their formation in extreme climatic regimes remain a significant, unresolved conundrum. Here we present a novel, process-based mechanism for the Villaggio del Pescatore Konservat-Lagerstätte (northeastern Italy; Late Cretaceous, 80 Ma), which preserves a diverse terrestrial and aquatic biota. Integrating high resolution synchrotron micro-analyses, bulk geochemistry, detailed taphonomy and palaeoclimate simulations we identify a dynamic, monsoon-paced tidal flat ecosystem within a carbonate coastal margin. Field and core records comprise metrescale packages of laterally persistent light–dark laminae; microstratigraphic, spectral and statistical analyses indicate a semidiurnal tidal regime with neap–spring modulation. MicroXRF/XRD mapping reveals that individual microlaminae within couplets share the same elemental inventory refuting a seasonal varve origin. Laminae chronometry, tied to the tidal interpretation, constrains net accumulation of the fossil bearing rhythmites to decadal (∼40 year) timescales. Geochemical proxies record alternating terrigenous rich, high TOC intervals and drier, better oxygenated intervals. Palaeoclimate model ensembles diagnose a vigorous, summer dominated monsoon domain at ∼29° N under greenhouse boundary conditions. We document that episodic monsoon enhanced flood and tropical cyclone pulses delivered sediment, nutrients, carcasses and plant debris to a microbially active, carbonate tidal flat; microbial mats rapidly stabilised and promoted early cementation, enabling exceptional soft tissue preservation. We propose a genetic model in which monsoon–cyclone forcing, tidal trapping and microbial sealing combine to produce decadal, daily resolved vertebrate Lagerstätten in greenhouse settings, offering predictive targets for similar deposits and deep time analogues for modern coastal change.

Keywords: Exceptional fossil preservation, Dinosauria, Crocodylomorpha, Arthropoda, Plants, Italy

“Stormbringer” — palaeoenvironmental reconstruction of Villaggio del Pescatore
The artwork shows a Tethyshadros insularis carcass and an Acynodon crocodylian on a storm-swept tropical tidal flat, beneath the monsoon clouds and a distant cyclone that the study identifies as the engine of the site’s formation.

 by palaeoartist Davide Bonadonna. 

 

Federico Fanti, Lorenzo Consorti, Marco Muscioni, Lorenzo Baldassari, Enrico Dinelli, Maurizio Polentarutti, Giorgio Bais, Alexander Farnsworth, Evelyn Kustatscher, Amalia Spina and Alfio Alessandro Chiarenza. 2026. Climate-extreme-driven Genesis of A Cretaceous Dinosaur Lagerstätte. Global and Planetary Change.  265, October 2026, 105589. DOI: doi.org/10.1016/j.gloplacha.2026.105589

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[Paleontology • 2026] Tametara mirim • Exceptional Brain and Ecological Diversity in the earliest Snakes

 

Tametara mirim

Simões, Sobral, Macrì, Ebel, Fachini, Martinelli, Nava, Paixão, Chiappe, Di-Poï & Hsiou, 2026

DOI: doi.org/10.1038/s41586-026-10809-9

Abstract

Understanding the ecological origin of snakes has remained a century-old challenge, hindered by an extremely sparse early fossil record and conflicting interpretations of fossil ecologies. Here we describe an exceptionally preserved Cretaceous fossil snake, Tametara mirim gen. et sp. nov., from Brazil, representing one of the earliest-diverging stem snakes. High-resolution micro-CT scans reveal unprecedented details of cranial nerves, inner ear and brain anatomy, enabling the most integrated reconstruction of stem snake neuroanatomy to date. Quantitative and qualitative endocast analyses demonstrate that Tametara had a brain morphology distinct from both other stem and extant snakes, revealing substantial early neuroanatomical disparity—and probably sensory functions—in snake evolution. Independent evidence from telencephalon shape and bone microstructure converges on a fossorial lifestyle for Tametara and non-fossorial for another stem snake: Dinilysia. These results indicate that major ecological transitions occurred early in snake evolution, and that known stem species do not represent the ancestral condition of crown snakes. Early snake evolution thus involved complex shifts in habitat use and sensory ecology, revealing greater ecological and neuroanatomical diversity than previously thought.

 

Systematic palaeontology

Squamata Oppel, 1811

Serpentes Linnaeus, 1758

Holotype (MPM 420) of Tametara mirim. 
 a, Photograph of the whole specimen with the articulated skull and postcranium in dorsal view. Ant, anterior; Bl, block number; Ce.V., cervical vertebrae; Do.V., dorsal vertebrae; Post, posterior; Sk, skull. b,c, Photographs of the skull in lateral (b) and dorsal (c) view. CB, compound bone; F, frontal; Oto, otoccipital; P, parietal; PFr, postfrontal; Pro, prootic; Ptg, pterygoid; Q, quadrate; Soc, supraoccipital; St, supratemporal. d–g, 3D renderings of an anterior precloacal (‘cervical’) vertebra in lateral (d) and anterolateral (e) views, and mid-precloacal (‘dorsal’) vertebra in dorsal (f) and left lateral (g) views. h–j, 3D renderings of the skull in the right lateral view (h) and with exposed brain endocasts in the right lateral (i) and dorsal (j) views. Mes., mesencephalon; Rho., rhombencephalon; Tel., telencephalon. Scale bars, 100 mm (a), 5 mm (b,c,h–j) and 1 mm (d–g). Specimen photos were taken by A.S.H.

Tametara mirim gen. et sp. nov.

Diagnosis. Tametara mirim can be distinguished from all other snakes based on the following combination of characters: postfrontal present but parietal (posterior) process absent*; parietal with posteromedial process present*; supraoccipital with sagittal crest, posterolaterally projecting nuchal crests*, well-developed anterolateral processes* and strongly overlapped by the parietal dorsally; otoccipitals not contacting each other medially (separated by posterior process of supraoccipital); quadrates with quadrate conch, suprastapedial process and pterygoid lappet; posterior surangular foramen present; precloacal vertebrae with well-developed and ventrolaterally oriented ...

Etymology. Tametara, meaning ‘adorned’ (referring to the pronounced sagittal crest of the holotype); mirim, meaning small-sized, in the native Brazilian, Tupí-Guaraní language.

Holotype. MPM 420 (Museu de Paleontologia de Marília, Marília, State of São Paulo, Brazil). Posterior half of a 3D-preserved skull and mandibles articulated with the anterior portion of the postcranium, including 103 presacral vertebrae.

Locality and age. The fossil was discovered by W.R.N. and G.M.X.P. in 2020, in William’s Quarry 2 at Sítio Paleontológico ‘José Martin Suárez’ (Presidente Prudente municipality, State of São Paulo, Brazil); Adamantina Formation, Bauru Group, Bauru Basin, late Santonian to early Campanian age (approximately 85–75 million years ago (Ma))22.

 

Tiago R. Simões, Gabriela Sobral, Simone Macrì, Roy Ebel, Thiago S. Fachini, Agustín G. Martinelli, William R. Nava, Giovanna M. X. Paixão, Luis M. Chiappe, Nicolas Di-Poï and Annie S. Hsiou. 2026. Exceptional Brain and Ecological Diversity in the earliest Snakes. Nature. DOI: doi.org/10.1038/s41586-026-10809-9 [22 July 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] New Fossil unveils the Dentary Anatomy of the rare lepidosauromorph Cargninia enigmatica from the Upper Triassic of Southern Brazil

 Cargninia enigmatica Bonaparte, Schultz, Soares & Martinelli, 2010, 

in Damke, Dalle-Laste,  Kerber, Roberto-da-Silva et Müller, 2026. 

DOI: doi.org/10.1002/ar.70268

Artwork by Márcio L. Castro.

Abstract

Nowadays, Lepidosauria is a diverse group represented by squamates and the rhynchocephalian tuatara. However, their origins date back to the end of the Permian Period, when the stem lineages Lepidosauromorpha and Archosauromorpha diverged. Within the lepidosauromorph stem lineage, a few species have been described with unstable phylogenetic placements. In Brazilian strata, the only representative of this lineage is the rare species Cargninia enigmatica. The taxon was found in Norian beds (upper portion of the Candelária Sequence) and is known from the posterior end of a dentary and a tentatively referred partial maxilla. Here, we describe a new specimen (CAPPA/UFSM 0519) referred to Cargninia enigmatica, consisting of a partial dentary recovered from the type locality. The specimen provides new anatomical information on the anterior portion of the dentary. In addition, for the first time, the phylogenetic placement of Cargninia enigmatica was investigated in a computational framework, and the results are congruent with previous suggestions that it represents a non-lepidosaur lepidosauromorph. Finally, the new specimen reveals details of the anatomy of the mandibular ramus of the trigeminal nerve, demonstrating that it shares a similar condition with its extant relatives.

Keywords: Caturrita Formation, Gondwana, Lepidosauromorpha, Norian, Pangea

Left dentary of CAPPA/UFSM 0519 in lateral view. (a) Photograph. (b) Interpretative drawing. (c) Detail of the rostralmost preserved teeth. (d) Additional details of the second and third preserved teeth. fo, foramina.

SYSTEMATIC PALEONTOLOGY

DIAPSIDA Osborn, 1903

SAURIA Macartney, 1802

LEPIDOSAUROMORPHA Gauthier, 1984 (sensu Gauthier et al., 1988)

Cargninia enigmatica Bonaparte et al., 2010

 Holotype: UFRGS-PV-1027-T, posterior end of a left dentary with five preserved teeth.

 Type locality, age, and horizon: Linha São Luiz site (29°33′45″S, 53°26′48″W), municipality of Faxinal do Soturno, Rio Grande do Sul, Brazil. Candelária Sequence of the Santa Maria Supersequence (Horn et al., 2014; Zerfass et al., 2003). These layers are early Norian in age (225.42 ± 0.37) (Langer et al., 2018).

New referred material: CAPPA/UFSM 0519, partial left dentary with several teeth. The specimen was collected from the type locality.

  Amended diagnosis: In addition to the unique traits of Cargninia enigmatica listed by Bonaparte et al. (2010) and Romo de Vivar et al. (2020), we recognize the following additional features based on the study of CAPPA/UFSM 0519 that distinguish the species from closely related taxa: the symphyseal region is medially recurved and formed by the Meckelian groove, and the presence of foramina restricted to the anterior region of the dentary.

A landscape from the Late Triassic of southern Brazil showing Cargninia enigmatica being observed by the sauropodomorph dinosaur Macrocollum itaquii. Artwork by Márcio L. Castro.

Lísie Vitória Soares Damke, Vitória Zanchett Dalle-Laste, Leonardo Kerber, Lúcio Roberto-da-Silva and Rodrigo Temp Müller. 2026. New Fossil unveils the Dentary Anatomy of the rare lepidosauromorph Cargninia enigmatica from the Upper Triassic of Southern Brazil. The Anatomical Record. DOI: doi.org/10.1002/ar.70268  [04 July 2026]

[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] Tylosaurus rex • A gigantic New Species of Tylosaurus (Squamata: Mosasauridae) from Texas: and A revised character list for phylogenetic analyses of Mosasauridae

Tylosaurus rex

Zietlow, Polcyn & Tykoski, 2026

 

hdl.handle.net/2246/7549 

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Abstract

At least four subfamily-level clades of mosasaurs are broadly recognized (Mosasaurinae, Plioplatecarpinae, Tylosaurinae, Halisaurinae), each of which independently evolved flippers and other aquatic adaptations, including large body size. Tylosaurine mosasaurs are distinguished from other mosasaurs, in part, by edentulous extensions of both upper and lower jaws, proportionally long tails, and poorly ossified limbs, and they were the first mosasaur clade to achieve gigantic (>8 m) body size. Several tylosaurine species are known from Europe, Asia, New Zealand, Africa, and Antarctica, but they were most common in the Western Interior Seaway of North America. Here, we describe a new species, Tylosaurus rex, sp. nov., from the Campanian of Texas and analyze tylosaurine in-group systematics using a significantly updated phylogenetic character list. Our new species is distinguished by a unique suite of characters, including some associated with increased jaw and neck musculature, and others that may be convergent with other giant mosasaur species (e.g., Mosasaurus). Body length estimates for specimens referred to our new species are consistently larger (7.7–13.2 m) than those for the largest Niobrara species, T. proriger (3.9–9.5 m), although it is unclear whether this is a taxonomic signal or taphonomic bias. Several specimens that we refer to T. rex were previously referred to T. proriger in various collections databases, and some of the traits distinguishing them had been previously attributed to ontogenetic differences. However, we rule out this possibility as specimens of T. proriger and T. rex that do overlap in size can be differentiated by unique suites of diagnostic characters. The implicit association between body size and ontogeny, as well as the general absence of reliable locality and stratigraphic data associated with historical collections of North American mosasaurs, raises the possibility of the presence of other currently unrecognized species, previously dismissed as ontogenetic stages of other species.

 

Keywords: Tylosaurus rex, Tylosaurus, Texas, Classification, Mosasauridae, Phylogeny 

The holotype for the newly described Tylosaurus rex is a giant specimen displayed at the Perot Museum of Nature and Science in Dallas that was first discovered in 1979.

 Perot Museum of Nature and Science

Tylosaurus rex, sp. nov.

A reconstruction of Tylosaurus rex in the Cretaceous-era Western Interior Seaway of North America

artwork by Alderon Games - Path of Titans

Zietlow, Amelia R.; Polcyn, Michael J. and Tykoski, Ronald S. 2026. A gigantic New Species of Tylosaurus (Squamata, Mosasauridae) from Texas: and A revised character list for phylogenetic analyses of Mosasauridae. Bulletin of the American Museum of Natural History. 482; DOI: 10.1206/0003-0090.482.1.1 https://hdl.handle.net/2246/7549

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