[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] 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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[Paleontology • 2025] Tainrakuasuchus bellator • Osteology, Taxonomy and Phylogenetic Affinities of A New pseudosuchian Archosaur from the Middle Triassic of southern Brazil

  

Tainrakuasuchus bellator 

 Müller, Garcia, Damke, Prestes de Bem, Fonseca, Doering, Schiefelbein & Laste, 2025

DOI: doi.org/10.1080/14772019.2025.2573750

Artwork by Caio Fantini. 

 

Abstract

Following the end-Permian mass extinction, archosaurs underwent rapid taxonomic and morphological diversification. While the avian lineage expanded into a broader range of ecological niches during the Late Triassic, the crocodilian lineage dominated ecosystems as early as the Middle Triassic, achieving an impressive range of morphological variation. Among the several pseudosuchian radiations that characterized the Middle Triassic, Poposauroidea stands out as one of the most enigmatic groups. From the Early to the Late Triassic, poposauroids evolved diverse body plans: some species developed dorsal ‘sails’, others became entirely edentulous, some adopted bipedal postures, and others occupied apex predator roles. In South America, the fossil record of Poposauroidea during the Middle Triassic is relatively scarce, being limited to Schultzsuchus loricatus, a relatively large-bodied predator known from fragmentary remains collected at a site within the Pinheiros–Chiniquá Sequence. In the present study, we describe Tainrakuasuchus bellator gen. et sp. nov., a new poposauroid from Brazil. The holotype was discovered at a locality known as the Posto Site, in the municipality of Dona Francisca (Pinheiros–Chiniquá Sequence; Middle Triassic). The specimen preserves a partial lower jaw, cervical and dorsal vertebrae, and an ilium. Tainrakuasuchus bellator gen. et sp. nov. is characterized by a slender mandible, ziphodont dentition and relatively elongated cervical vertebrae, representing a new medium-sized predatory archosaur. Phylogenetic analyses suggest affinities with Mandasuchus tanyauchen, a putative poposauroid from the Tanzanian Manda beds. The close relationship between these taxa, along with the strong faunal similarities between the respective geological units, reinforces the correlation between units and supports a Ladinian age. Finally, the discovery of Tainrakuasuchus bellator gen. et sp. nov. expands the known taxonomic diversity of the Dinodontosaurus Assemblage Zone and provides new insights into the key role played by pseudosuchians in the complex ecosystems of the Middle Triassic of south-western Gondwana.

 

Keywords: cladistics, Gondwana, Ladinian, Paracrocodilomorpha, Poposauroidea

Systematic palaeontology

Archosauria Cope, Citation1869

Pseudosuchia Zittel, Citation1887–1890

Paracrocodylomorpha Parrish, Citation1993

Tainrakuasuchus bellator gen. et sp. nov.

Etymology. The combination of Guarani tain, tooth, and rakua, pointed, with Greek suchus, crocodile; referring to the pointed teeth of the lower jaw. The specific epithet bellator is derived from Latin, meaning ‘warrior’ or ‘fighter’. It serves as a tribute to the people of Rio Grande do Sul, honouring their historical resilience and enduring spirit, particularly in light of the recent severe flooding that has impacted the state.

 Artistic representation of a Middle Triassic landscape of southern Brazil depicting Tainrakuasuchus bellator gen. et sp. nov.

Artwork by Caio Fantini.

 

Rodrigo Temp Müller, Mauricio Silva Garcia, Lísie Vitória Soares Damke, Fabiula Prestes de Bem, André de Oliveira Fonseca, Mariana Doering, Jeung Hee Schiefelbein and Vitória Zanchett Dalle Laste. 2025. Osteology, Taxonomy and Phylogenetic Affinities of A New pseudosuchian Archosaur from the Middle Triassic of southern Brazil. Journal of Systematic Palaeontology. 23(1); 2573750. DOI: doi.org/10.1080/14772019.2025.2573750 [12 Nov 2025]

[Paleontology • 2025] Wadisuchus kassabi • An early dyrosaurid (Pseudosuchia: Crocodyliformes) from the Campanian of Egypt sheds light on the Origin and Biogeography of Dyrosauridae

 

Wadisuchus kassabi

Saber, Salem, Ouda, Gohar, El-Sayed, O’Connor & Sallam, 2025 

DOI: doi.org/10.1093/zoolinnean/zlaf134

Paleoart by Nathan Dehaut. 

Abstract

Dyrosauridae are a clade of crocodyliforms characterized by diverse cranial morphologies and a broad palaeogeographic distribution from the Late Cretaceous to the Palaeogene. However, their early evolutionary history remains poorly understood due to a significant fossil gap during the Campanian. Here, we describe Wadisuchus kassabi gen. et sp. nov., an early-diverging dyrosaurid from the middle Campanian Quseir Formation of Egypt, based on two partial skulls and three partial mandibles. This new taxon displays transitional cranial features—including reduced premaxillary alveoli, modified occlusion patterns, and dorsally positioned external nares—that clarify aspects of cranial evolution related to longirostry in early dyrosaurids. Phylogenetic analyses consistently recover Wadisuchus as the earliest-diverging dyrosaurid, closely related to Chenanisuchus and distinct from Elosuchus, supporting a transition from dyrosauroids to dyrosaurids. Its Campanian age extends the temporal range of the clade and suggests that transatlantic dispersal from Africa to South America occurred earlier than previously recognized. Alongside Brachiosuchus kababishensis from Sudan, the new Egyptian taxon also implies that reverse dispersal into Africa preceded the Maastrichtian. Wadisuchus provides critical insights into the early diversification, palaeobiogeography, and cranial evolution of Dyrosauridae, confirming longirostry as an early-acquired trait and highlighting North Africa as a key region in their origin.

Campanian, Quseir Formation, Egypt, North Africa, Dyrosauridae, phylogeny

Life reconstruction of Wadisuchus kassabi from the Late Cretaceous of Egypt, showing an adult capturing a lungfish in a wetland, with a juvenile nearby. The scene highlights the ancient ecosystem, including turtles and lush vegetation, based on fossil evidence from the Quseir Formation.

Paleoart by Nathan Dehaut. / MUVP—Scientific supervision

Wadisuchus kassabi gen. et sp. nov.

Sara Saber, Belal S Salem, Khaled Ouda, Abdullah S Gohar, Sanaa El-Sayed, Patrick M O’Connor and Hesham M Sallam. 2025. An early dyrosaurid (Wadisuchus kassabi gen. et sp. nov.) from the Campanian of Egypt sheds light on the Origin and Biogeography of Dyrosauridae. Zoological Journal of the Linnean Society. 205(2) zlaf134. DOI: doi.org/10.1093/zoolinnean/zlaf134 [27 October 2025]

[Paleontology • 2025] Thilastikosuchus scutorectangularis • A New notosuchian (Crocodyliformes: Mesoeucrocodylia) from the Quiricó Formation, Lower Cretaceous, Sanfranciscana Basin, Brazil

Thilastikosuchus scutorectangularis

 de Carvalho, Santos, Pinto & Santucci, 2025 

DOI: doi.org/10.1080/02724634.2025.2452947 

   x.com/palaeodaniel

ABSTRACT

Notosuchians comprise a clade of mostly terrestrial crocodyliforms generally found in Cretaceous Gondwanan deposits. They evolved into many forms and some species show convergences with mammalian features such as the development of a high degree of heterodonty and multicuspid teeth. South American deposits concentrate the highest number of described notosuchian species, which is more than twice the number of taxa known from strata elsewhere. Here, a novel candidodontid notosuchian, Thilastikosuchus scutorectangularis, gen. et sp. nov., is presented and described, comprising a new monospecific genus and the oldest notosuchian record found in Brazil, and likely from South America. This new taxon lacks the sharp hypertrophied caniniform teeth of closely related forms, such as Malawisuchus and Pakasuchus, but shares the posterior molariform teeth with increasingly wider crowns and denticulated cingula. Additionally, the phylogenetic analysis with the inclusion of the new Brazilian material places Candidodontidae as the earliest notosuchian radiation, shedding new light into its origins.

Thilastikosuchus scutorectangularis, gen. et sp. nov.

Thilastikosuchus scutorectangularis gen. et sp. nov.

reconstruction by Felipe Elias

Joyce Celerino de Carvalho, Daniel Martins dos Santos, Ricardo Lourenço Pinto and Rodrigo Miloni Santucci. 2025. Anatomical Description and Systematics of A New notosuchian (Mesoeucrocodylia; Crocodyliformes) from the Quiricó Formation, Lower Cretaceous, Sanfranciscana Basin, Brazil. Journal of Vertebrate Paleontology. e2452947. DOI: doi.org/10.1080/02724634.2025.2452947  

  x.com/palaeodaniel/status/1891840889435115539

[Paleontology • 2024] Benggwigwishingasuchus eremicarminis • A New pseudosuchian (Archosauria: Pseudosuchia) from the Favret Formation of Nevada reveals that Archosauriforms occupied Coastal Regions globally during the Middle Triassic

Benggwigwishingasuchus eremicarminis 

Smith, Klein, Sander & Schmitz, 2024 

DOI: 10.1098/rsbl.2024.0136

Abstract

Recent studies suggest that both stem- and crown-group Archosauria encompassed high ecological diversity during their initial Triassic radiation. We describe a new pseudosuchian archosaur, Benggwigwishingasuchus eremicarminis gen. et sp. nov., from the Anisian (Middle Triassic) Fossil Hill Member of the Favret Formation (Nevada, USA), a pelagic setting in the eastern Panthalassan Ocean characterized by the presence of abundant ammonoids and large-bodied ichthyosaurs. Coupled with archosauriforms from the eastern and western Tethys Ocean, Benggwigwishingasuchus reveals that pseudosuchians were also components of Panthalassan ocean coastal settings, establishing that the group occupied these habitats globally during the Middle Triassic. However, Benggwigwishingasuchus, Qianosuchus, and Ticinosuchus (two other pseudosuchians known from marine sediments) are not recovered in a monophyletic group, demonstrating that a nearshore marine lifestyle occurred widely across Archosauriformes during this time. Benggwigwishingasuchus is recovered as part of an expanded Poposauroidea, including several taxa (e.g. Mandasuchus, Mambawakalae) from the Middle Triassic Manda Beds of Tanzania among its basally branching members. This implies a greater undiscovered diversity of poposauroids during the Early Triassic, and supports that the group, and pseudosuchians more broadly, diversified rapidly following the End-Permian mass extinction.

Class Reptilia Linnaeus, 1758

Archosauriformes  

Archosauria  

Pseudosuchia  

Poposauroidea  

Benggwigwishingasuchus eremicarminis gen. et sp. nov.
Holotype skeleton (LACM-DI 158616) (a) (pelvis block mirrored for articulation); and interpretive drawing (b)  

Genus Benggwigwishingasuchus

Benggwigwishingasuchus eremicarminis gen. et sp. nov.

  Holotype: LACM-DI 158616, a partially articulated skeleton, including some cranial elements but most of the axial column, girdles and limbs.

  Diagnosis: Mid-sized pseudosuchian (total length: approximately 1.5 m; femur length: 17.75 cm) diagnosed by the following unique combination of characters (*indicates autapomorphy, †indicates autapomorphy inferred from phylogenetic analysis): semilunate eminence on middle of ventral ramus of prefrontal*; ventral ramus of prefrontal broadly exposed in lateral view, extensive ventrally and excludes lacrimal from orbit; supratemporal fossa well-exposed dorsally on parietal; high cervical vertebrae count (10–11); low dorsal vertebrae count (10–11)*; dorsal vertebrae with well-developed laminae and deep infradiapophyseal fossae; anterior caudal vertebrae with well-developed, spatulate ribs; anterior caudal ribs asymmetrical in dorsal view, with diagonal bevel on posterolateral edge*; weakly sinusoidal fibular shaft; metatarsal IV longer than metatarsal III†; metatarsal IV subequal in length to metatarsal II†; robust lateral plantar tubercle on ventral face of metatarsal V; dorsal osteoderms in one-to-one, mirrored alignment in dorsal aspect†; osteoderms with indentations creating an ‘hourglass’ waisting in dorsal view*; osteoderms with multiple short spikes on lateral and medial edges.

  Etymology: The generic name combines ‘Benggwi Gwishinga’ from the Shoshone term for ‘catching fish’, with ‘suchus’, the Greek term for Sobek, the Egyptian crocodile-headed god. The specific epithet combines the Latin ‘erema’ and ‘carminis’, meaning ‘desert song’, and honours Elaine Kramer and Monica Shaffer, and their love of the palaeontology, museums, and opera of the southwestern USA. The binomen is intended to translate roughly as ‘Fisherman Croc's desert song’.

Middle Triassic palaeogeographic map with localities of Archosauriformes known from marine settings.

  Locality and age: Fossil Hill Member of the Favret Formation, Favret Canyon, Augusta Mountains, Pershing County, Nevada, USA. The type locality, LACM LOC 8057, is near the top of the north slope of Favret Canyon at an altitude of 1911 m. The horizon pertains to the Frechites occidentalis Zone, which is late Anisian (Middle Triassic) in age.

Nathan D. Smith, Nicole Klein, P. Martin Sander and Lars Schmitz. 2024. A New pseudosuchian from the Favret Formation of Nevada reveals that Archosauriforms occupied Coastal Regions globally during the Middle Triassic. Biol. Lett. 2020240136. DOI: doi.org/10.1098/rsbl.2024.0136

[Paleontology • 2024] Parvosuchus aurelioi • A New small-sized predatory pseudosuchian Archosaur (Pseudosuchia: Gracilisuchidae) from the Middle-Late Triassic of Southern Brazil

 Parvosuchus aurelioi  

Müller, 2024 

   

DOI: 10.1038/s41598-024-63313-3

 Artwork by Matheus Fernandes.

Abstract

Before the rise of dinosaurs and pterosaurs, pseudosuchians—reptiles from the crocodilian lineage—dominated the Triassic land ecosystems. This lineage diversified into several less inclusive clades, resulting in a wide ecomorphological diversity during the Middle and Late Triassic. Some giant pseudosuchians occupied the top of the trophic webs, while others developed extensive bony armor as a defense mechanism, which later evolved as a convergence in the avemetatarsalian lineage. On the other hand, there were groups like the Gracilisuchidae, which was composed of carnivorous forms with lightweight build and less than 1 m in length. The fossil record of gracilisuchids is geographically restricted to China and Argentina, with one ambiguous record from Brazil. In the present study, the first unambiguous gracilisuchid from Brazil is described. Parvosuchus aurelioi gen. et sp. nov. comes from the Dinodontosaurus Assemblage Zone of the Santa Maria Formation, which is associated with the Ladinian-Carnian boundary. Composed of a complete cranium, vertebrae, pelvic girdle and hindlimbs, the new species nests with Gracilisuchus stipanicicorum and Maehary bonapartei in a phylogenetic analysis. Its discovery fills a taxonomic gap in Brazilian pseudosuchian fauna and reveals the smallest known member of this clade from the Dinodontosaurus Assemblage Zone, highlighting the diversity of pseudosuchians during the moment that preceded the dawn of dinosaurs.

 

Skull and lower jaws of Parvosuchus aurelioi gen. et sp. nov.
Holotype (CAPPA/UFSM 0412)
 from the Pinheiros-Chiniquá Sequence (Ladinian-Carnian boundary) of the Santa Maria Supersequence, southern Brazil. 

Provenance of Parvosuchus aurelioi gen. et sp. nov. 
(a) Location and geological context of the Linha Várzea 2 site, Paraíso do Sul, Rio Grande do Sul, Brazil. (b) General view of the Linha Várzea 2 site (taken in January 2023).
(c) Hypothetical reconstruction of the skeleton of the Parvosuchus aurelioi gen. et sp. nov. depicting (in orange) the preserved portions of CAPPA/UFSM 0412. Unpreserved portions are based on the skeletal reconstruction of Gracilisuchus stipanicicorum by Jorge González.

Systematic paleontology

Archosauria Cope, 1869

Pseudosuchia Zittel, 1887–1890

Gracilisuchidae Butler et al., 2014

Parvosuchus aurelioi gen. et sp. nov. 

Holotype: CAPPA/UFSM 0412, a partial skeleton, including a skull with lower jaws, 11 dorsal vertebrae, two sacral vertebrae, a complete pelvic girdle, both femora (lacking the distal portion), partial left tibia, partial left fibula, and left calcaneum.

Etymology: The genus name combines the Latin word “parvus” (= small) and the Greek word “suchus” (= crocodile). The specific epithet honors Pedro Lucas Porcela Aurélio for his passion for paleontology and prospecting, as well as for having discovered the fossil material described here.

Results of the phylogenetic analysis and diversity of the Dinodontosaurus Assemblage Zone of Brazil. (a) Time-calibrated reduced strict consensus tree depicting the phylogenetic position of Parvosuchus aurelioi gen. et sp. nov. Number on nodes represent Bremer support values higher than 1. The temporal bars for each OTU represent the maximum and minimum ages of each geological unit. Divergence times set as approximately 1 million years. (b) Percentage of taxonomic groups recorded in the Dinodontosaurus Assemblage Zone according to the number of species. (c) Approximate body length of pseudosuchian species from the Dinodontosaurus ZA.

Artistic representation of a Middle-Late Triassic landscape of southern Brazil.
(a) A large Prestosuchus chiniquensis feeds on the carcass of a dicynodont while individuals of Parvosuchus aurelioi gen. et sp. nov. compete for scraps. (b) and (c) depict details of individuals of Parvosuchus aurelioi gen. et sp. nov. Artwork by Matheus Fernandes.

Rodrigo T. Müller. 2024. A New small-sized predatory pseudosuchian Archosaur from the Middle-Late Triassic of Southern Brazil. Scientific Reports. 14, 12706. DOI: 10.1038/s41598-024-63313-3

[Paleontology • 2024] Garzapelta muelleri • A New aetosaur (Archosauria: Pseudosuchia) from the Late Triassic (middle Norian) middle Cooper Canyon Formation, Dockum Group, Texas, USA, and its implications on our understanding of the morphological disparity of the aetosaurian dorsal carapace

 Garzapelta muelleri

 Reyes, Martz &  Small, 2024

  

DOI: 10.1002/ar.25379

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Abstract

The Late Triassic Dockum Group in northwestern Texas preserves a rich diversity of pseudosuchian taxa, particularly of aetosaurs. In this contribution, we present Garzapelta muelleri gen. et sp. nov., a new aetosaur from the Late Triassic middle Cooper Canyon Formation (latest Adamanian–earliest Revueltian teilzones) in Garza County, Texas, based on an associated specimen that preserves a significant portion of its dorsal carapace. The carapace of G. muelleri exhibits a striking degree of similarity between that of the paratypothoracin Rioarribasuchus chamaensis and desmatosuchins. We quantitatively assessed the relationships of G. muelleri using several iterations of the matrix. Scoring the paramedian and lateral osteoderms of G. muelleri independently results in conflicting topologies. Thus, it is evident that our current matrix is limited in its ability to discern the convergence within this new taxon and that our current character lists are not fully accounting for the morphological disparity of the aetosaurian carapace. Qualitative comparisons suggest that G. muelleri is a Rioarribasuchus-like paratypothoracin with lateral osteoderms that are convergent with those of desmatosuchins. Although the shape of the dorsal eminence, and the presence of a dorsal flange that is rectangular and proportionately longer than the lateral flange are desmatosuchin-like features of G. muelleri, the taxon does not exhibit the articulation style between the paramedian and lateral osteoderms which diagnose the Desmatosuchini (i.e., a rigid interlocking contact, and an anteromedial edge of the lateral osteoderm that overlaps the adjacent paramedian osteoderm).

Keywords: Aetosaur, Dockum Group, Late Triassic, Revueltian, Texas

William A. Reyes, Jeffrey W. Martz, Bryan J. Small. 2024. Garzapelta muelleri gen. et sp. nov., A New aetosaur (Archosauria: Pseudosuchia) from the Late Triassic (middle Norian) middle Cooper Canyon Formation, Dockum Group, Texas, USA, and its implications on our understanding of the morphological disparity of the aetosaurian dorsal carapace. The Anatomical Record. DOI: 10.1002/ar.25379

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[Paleontology • 2022] Mambawakale ruhuhu • A New Pseudosuchian Archosaur (Pseudosuchia) from the Middle Triassic Manda Beds of Tanzania

Mambawakale ruhuhu 

Butler, Fernandez, Nesbitt, Leite & Gower, 2022

 

DOI: 10.1098/rsos.211622 

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 Life reconstruction by Gabriel Ugueto twitter.com/SerpenIllus

Abstract

The Manda Beds of southwest Tanzania have yielded key insights into the early evolutionary radiation of archosaurian reptiles. Many key archosaur specimens were collected from the Manda Beds in the 1930s and 1960s, but until recently, few of these had been formally published. Here, we describe an archosaur specimen collected in 1963 which has previously been referred to informally as Pallisteria angustimentum. We recognize this specimen as the type of a new taxon, Mambawakale ruhuhu gen. et sp. nov. The holotype and only known specimen of M. ruhuhu comprises a partial skull of large size (greater than 75 cm inferred length), lower jaws and fragments of the postcranium, including three anterior cervical vertebrae and a nearly complete left manus. Mambawakale ruhuhu is characterized by several cranial autapomorphies that allow it to be distinguished with confidence from all other Manda Beds archosaurs, with the possible exception of Stagonosuchus nyassicus for which comparisons are highly constrained due to very limited overlapping material. Phylogenetic analysis suggests that M. ruhuhu is an early diverging pseudosuchian, but more precise resolution is hampered by missing data. Mambawakale ruhuhu is one of the largest known pseudosuchians recovered to date from the Middle Triassic.

Keywords: phylogeny, Pseudosuchia, Triassic, Archosauria, Tanzania

 

Figure 1. Photographs showing the collection of NHMUK R36620, holotype of Mambawakale ruhuhu, in 1963. Alan Charig is sat in the bottom right of the frame in the top left image, and is accompanied by Alfred ‘Fuzz’ Crompton. The top left and bottom right images also show Tanzanians (names unfortunately not recorded in archival material) who were employed by the 1963 expedition team and were critical to its success, discovering many of the fossil sites, constructing roads and carrying excavated fossils out of the field.

Photographs courtesy of Barry Cox and Steve Tolan. Original slides of these photographs are archived at NHMUK.

 Photographs of the skull of NHMUK R36620, holotype of Mambawakale ruhuhu, in right lateral (a) and left lateral (b) views.

Systematic Palaeontology

Archosauria 1869–1870

Pseudosuchia 1887–1890

Mambawakale ruhuhu gen. et sp. nov.

Holotype. NHMUK R36620, partial skull including premaxillae, maxillae, vomers, palatines, pterygoids, ectopterygoids and fragments of the jugals and basipterygoid, with associated hemimandibles, hyoids and isolated maxillary or dentary teeth. These cranial remains are associated (see below) with an incomplete postcranium, including an atlantal intercentrum, partial axis and partial third cervical vertebra, a mostly complete left manus, and additional poorly preserved fragments.

Etymology. Mambawakale, from the Kiswahili words mamba, meaning crocodile, and wakale, meaning ancient. The species name refers to the Ruhuhu Basin from which the type specimen and other taxa from the Manda Beds were collected.

Locality and stratigraphy. Field locality U15/1 of Attridge et al. [1964], Lifua Member of the Manda Beds (Middle Triassic: ?Anisian), Ruhuhu Basin, southwest Tanzania. ...

 Life reconstruction of Mambawakale ruhuhu.
 Only the skull, mandible and a few postcranial elements are known for Mambawakale ruhuhu, so the rest of the body, tail and limbs are reconstructed based on the anatomy of hypothesized close relatives of similar size.

Illustration by Gabriel Ugueto, who retains the copyright.

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Richard J. Butler, Vincent Fernandez, Sterling J. Nesbitt, João Vasco Leite and David J. Gower. 2022. A New Pseudosuchian Archosaur, Mambawakale ruhuhu gen. et sp. nov., from the Middle Triassic Manda Beds of Tanzania. Royal Society Open Science. 9: 211622. DOI: 10.1098/rsos.211622

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