[Paleontology • 2026] Kank australis • New unenlagiid (Theropoda: Unenlagiidae) from the Chorrillo Formation (Late Cretaceous, Maastrichtian), SW Patagonia, Argentina

 

Kank australis

Motta, Rolando, Rozadilla, Agnolín, Egli, Herrera, Chimento, Coco, Tsuihiji, Manabe, Pol & Novas, 2026

 

DOI: doi.org/10.1080/02724634.2026.2656456 

A reconstruction by Gabriel Díaz Yantén

 

ABSTRACT

Unenlagiids constitute a group of paravian theropods up to now represented in Gondwanan landmasses. They are particularly diverse in northern Patagonia, where at least seven species were discovered in Upper Cretaceous beds. In southern Patagonia, by contrast, the record is restricted to a few isolated remains of indeterminate taxa from Argentina and Chile. The aim of the present contribution is to describe an unenlagiid, Kank australis gen. et sp. nov. from the Maastrichtian beds of southern Santa Cruz, southern Patagonia, Argentina. Kank australis is represented by vertebrae, isolated pedal phalanges, and shed teeth. The holotype individual has a unique combination of characters, including a highly pneumatized cervical vertebra with well-developed parapophysis and carotid processes. Further, a pedal phalanx II-2 resembles those of troodontids due the reduction of the distal condyles, and differs from other known unenlagiids. The apomorphic condition of the few available elements suggests that Kank australis was probably distinct from its kin and reinforces the hypothesis that Unenlagiidae was a morphologically disparate clade.

SYSTEMATIC PALEONTOLOGY

DINOSAURIA OWEN, 1842

SAURICHIA SEELEY, 1888

THEROPODA MARSH, 1881

PARAVES SERENO, 1997

UNENLAGIIDAE (Bonaparte, 1999)

KANK AUSTRALIS gen. et sp. nov.

Diagnosis—Medium-sized unenlagiid (phalanges similar in size to Neuquenraptor argentinus estimated in ∼27 kg; Motta, 2023) showing the following combination of characters (autapomorphies marked by an asterisk): (1) dentary teeth having mesial carinae restricted to the apical third of the crown (shared with Austroraptor); (2) labiolingually compressed maxillary teeth “8” in cross-section (shared with Buitreraptor); (3) dentary teeth having a crenulate mesial carina restricted to its apical third; (4) cervicodorsal vertebra having three pneumatic foramina on its ventral surface*; (5) cervicodorsal vertebra having epipophyseal fossa*; and (6) phalanx 2-II showing reduced distal condyles and collateral pits located very close to the anterodorsal corner of the condyles (shared with troodontids).

Etymology—“Kank,” in reference to the “elder Rhea,” who created the constellation Choiols (Southern Cross constellation) in the Aonikenk mythology, and “australis,” which means “from south” in Latin, in reference to the southern latitude where this dinosaur was found.

 

Matías J. Motta, Alexis M. Aranciaga Rolando, Sebastián Rozadilla, Federico L. Agnolín, Federico Brissón Egli, Gerardo P. Álvarez Herrera, Nicolás R. Chimento, Gastón Lo Coco, Takanobu Tsuihiji, Makoto Manabe, Diego Pol and Fernando E. Novas. 2026. New unenlagiid from the Chorrillo Formation (Late Cretaceous, Maastrichtian), SW Patagonia, Argentina. Journal of Vertebrate Paleontology. e2656456. DOI: doi.org/10.1080/02724634.2026.2656456  [28 May 2026]

https://newsroom.taylorandfrancisgroup.com/heron-like-fish-eating-dinosaur-from-70-million-years-ago-discovered-in-argentina

https://www.macnconicet.gob.ar/kank-australis-el-nuevo-raptor-descubierto-en-la-patagonia-argentina

[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] Acutodon villeveyracensis • A New pan-shinisaur Lizard (Anguimorpha) from the lower Campanian of Villeveyrac (Hérault, France)

Acutodon villeveyracensis 

Jansen, Augé, Garcia, Otero & Valentin, 2026

DOI: doi.org/10.1080/02724634.2026.2636649 

Artwork by Olivier Jansen

ABSTRACT

The Chinese crocodile lizard (Anguimorpha, Pan-Shinisaurus Shinisaurus crocodilurus) is an endangered species inhabiting the lowland rainforests of southeastern China and northern Vietnam. The evolutionary history of this clade remains poorly understood, as only five fossil species and a few fossil specimens are described from the Lower Cretaceous of China and the Cenozoic of Europe and North America, revealing a considerable gap in the fossil record. A new anguimorph, Acutodon villeveyracensis gen. et sp. nov., is described from the lower Campanian (Upper Cretaceous) locality of Villeveyrac (Hérault, France), corresponding to a freshwater subtropical paleoenvironment. The species is attributed to a pan-shinisaur anguimorph based on a toothed maxilla sharing multiple characters with the extant Sh. crocodilurus and its fossil relatives, notably tall, tapered, and recurved teeth, with mesiodistally constricted tooth bases lacking basal infoldings but possessing medial resorption pits, and a posteromedially shifted anterior superior alveolar foramen. This Cretaceous record is the oldest in Europe for pan-shinisaur lizards. It pre-dates the occurrence of this clade in Europe by around 30 Myr, raising questions about the paleobiogeographic history of pan-shinisaur lizards.

Acutodon villeveyracensis holotype and unique material (UP.VIL.2010.55). Photographs, virtual reconstruction, and interpretative drawings of the maxilla in A, labial; B, lingual; C, occlusal; and D, dorsal views. Note that the posteriormost tooth was lost after CT scanning.

Abbreviations: asaf, anterior superior alveolar foramen; ce, cutting edge; cl, crista lateralis; ct, crista transversalis; fp, facial process; lf, labial foramina; lic, lamina intercristalis; lpp, lateral premaxillary process; lr, lacrimal recess; mpp, medial premaxillary process; ps, palatal shelf; rp, resorption pit; sds, supradental shelf. Scale bar equals 10 mm.

Details of the teeth of Acutodon villeveyracensis holotype and unique material (UP.VIL.2010.55) from the virtual reconstruction.
A, morphology in anterior view; B, section in median plane; C, section in horizontal plane.

Abbreviations: asaf, anterior superior alveolar foramen; c, cement; cl, crista lateralis; ct, crista transversalis; d, dentine; lf, labial foramen; lpp, lateral premaxillary process; m, maxilla; mpp, medial premaxillary process; ps, palatal shelf; t1–t4, teeth numbered from front to back. Scale bar equals 2 mm.

SQUAMATA Oppel, 1811

ANGUIMORPHA Fürbringer, 1900

PAN-SHINISAURUS sensu Smith and Gauthier, 2013

ACUTODON gen. nov.

ACUTODON VILLEVEYRACENSIS, gen. et sp. nov.

Diagnosis—Large anguimorph lizard characterized by the following combination of characters: the teeth are tall, thin, and possess a tapered apex; anterior teeth are strongly posteriorly recurved, but the most posterior teeth are straight; the teeth lack striations and basal infoldings; the base of the teeth expands lingually but is strongly anteroposteriorly compressed, and is covered in a thin layer of cementum; the crowns have a faint cutting edge, restricted to the most apical portion; medial resorption pits are ...

Etymology—‘acutus’ (Latin), sharp, pointed, piercing, and thin; ‘ὀδόντος’ (Greek), teeth; the genus name refers to the tapered, sharp, and thin teeth of this new genus; ‘villeveyracensis’ (Latin) from the locality of Villeveyrac, department of Hérault, France, where this new lizard taxon has been found.

Acutodon villeveyracensis
Paleoartistic reconstruction of the new genus and species of pan-shinisaur lizard from the lower Campanian of Villeveyrac (Hérault, France). Original artwork by Olivier Jansen.

Olivier Jansen, Marc Augé, Geraldine Garcia, Olga Otero and Xavier Valentin. 2026. A New pan-shinisaur Lizard (Anguimorpha) from the lower Campanian of Villeveyrac (Hérault, France). Journal of Vertebrate Paleontology. DOI: doi.org/10.1080/02724634.2026.2636649  [20 May 2026]

[PaleoMammalogy • 2026] Cimolodon desosai • Cranial and Postcranial Remains of A New Species of Cimolodon (Multituberculata: Cimolodontidae) from the Upper Cretaceous (Campanian) El Gallo Formation of Baja California, México

Cimolodon desosai

Mantilla, Newbins, Fastovsky, Zhang, Montellano-Ballesteros, Alcántara & Chen, 2026

DOI: doi.org/10.1080/02724634.2026.2641109

Illustration by Andrey Atuchin

ABSTRACT

Late Cretaceous mammals from North America are predominantly known from isolated teeth and fragmentary jaws and from localities representing coastal lowlands along the Western Interior Seaway. Here, we report craniodental and associated postcranial remains of a new species of the cimolodontid multituberculate genus Cimolodon from the Upper Cretaceous (Campanian) El Gallo Formation of Baja California, México. The specimen was deposited along the Pacific Coast between 75.17 ± 0.30 Ma and 74.55 ± 0.18 Ma. It represents the most complete mammal known from the Mesozoic of México and one of the best known cimolodontan multituberculates from North America. Morphologically, the new species, Cimolodon desosai, is most like C. nitidus, but differences include upper anterior premolar shape, molar cusp formulae, and relative length proportions of the cheek teeth. Phylogenetic analysis supports placement of the new species within Cimolodon and Ptilodontoidea, but uncertainties remain regarding relationships among cimolodontan families. Using the craniodental and postcranial data, we quantitatively reconstruct C. desosai as a small-bodied (∼100 g), animal-dominated omnivore with a scansorial locomotor mode. With the new taxonomic occurrence, the El Gallo mammalian local fauna is now known from 16 specimens referred to three multituberculate species (Mesodma cf. M. formosa, ?Stygimys sp., and Cimolodon desosai), one metatherian (Pediomys sp.), and one eutherian (Gallolestes pachymandibularis). Although further sampling is needed, the mammalian local fauna presently shows greatest biogeographic affinities with the Terlingua local fauna of western Texas.

SYSTEMATIC PALEONTOLOGY

MAMMALIA Linnaeus, 1758

MULTITUBERCULATA Cope, 1884

CIMOLODONTA McKenna, 1975

PTILODONTOIDEA Sloan and Van Valen, 1965

CIMOLODONTIDAE McKenna, 1975

CIMOLODON Marsh, 1889

CIMOLODON DESOSAI, sp. nov.

Partial cranium of the holotype of Cimolodon desosai (IGM 14691).
Images are three-dimensional surface renderings from μCT scans in: A, anterior; B, stereo dorsal; C, stereo ventral; D, left lateral; and E, right lateral views of the partial cranium; and F, occlusal view of the right upper cheek tooth row in high magnification. Dashed white lines represent interpreted position of cranial bone sutures.

Abbreviations: al, anterior lamina; fr, frontal; iof, intraorbital foramen; mx, maxilla; na, nasal; naf, nasal foramen; otc, orbitotemporal canal; pa, parietal; pav, palatal vacuity; pmx, premaxilla; pop, postorbital process; sq, squamosal; zpm, zygomatic process of the maxilla. Scale bar equals 10 mm for A–E and 2 mm for F.

Cimolodon desosai on the tree with a fruit in its mouth. It was about the size of a golden hamster. It likely scampered on the ground and in the trees and ate fruits and insects.

Illustration by Andrey Atuchin

 

 

Gregory P. Wilson Mantilla, Isiah R. Newbins, David E. Fastovsky, Yue Zhang, Marisol Montellano-Ballesteros, Dalia García Alcántara and Meng Chen. 2026. Cranial and Postcranial Remains of A New Species of Cimolodon (Mammalia, Multituberculata, Cimolodontidae) from the Upper Cretaceous (Campanian) El Gallo Formation of Baja California, México. Journal of Vertebrate Paleontology. e2641109. DOI: doi.org/10.1080/02724634.2026.2641109  [22 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] The ontogenetically youngest known pachycephalosaur (Dinosauria: Ornithischia) postcranium

 

juvenile Pachycephalosauria indet. (CMNFV 22039)
Life reconstruction in an environment typical of the upper Maastrichtian Frenchman Formation, Saskatchewan. 

in Moore, Evans, Ryan, Patterson et Mallon, 2026. 

  DOI: doi.org/10.1080/02724634.2026.2616325

Illustration by Kaitlin Lindblad. 

 x.com/Jordan_Mallon

 

ABSTRACT

Pachycephalosaurian dinosaurs are represented in the fossil record primarily by their taphonomically resistant frontoparietal domes that developed fully only at maturity. Consequently, the postcranial record of Pachycephalosauria is poor, particularly for immature forms. Here, we describe the ontogenetically youngest known, and Canada’s second-most complete, pachycephalosaur postcranium, collected from the uppermost Maastrichtian Frenchman Formation, Saskatchewan. Despite its small size (estimated total length ∼90 cm), the skeleton shows several characters diagnostic of Pachycephalosauria, including a double ridge-and-groove articulation on the pre- and postzygapophyses of the dorsal neural arches, a medial flange on the postacetabular process of the ilium, and a highly reduced pubis that contributes only minimally to the acetabular margin. Histological sectioning of the crural bones shows an immature woven bone texture. The absence of cyclical or annual growth indicators suggests that this specimen was less than a year old at the time of death. Phylogenetic analysis recovers the specimen as a member of Pachycephalosaurinae, perhaps related to Prenocephale, but the lack of cranial data for our specimen and the complementary lack of postcranial data for other pachycephalosaurs make this determination tenuous. Spatiotemporal considerations suggest a possible but currently untestable affiliation with Sphaerotholus buchholtzae. The relatively long hindlimbs of the juvenile compared with those of adult pachycephalosaurs indicate probable negative ontogenetic allometry in the hindlimbs.

 Preserved elements (in red) of juvenile Pachycephalosauria indet. (CMNFV 22039).
 The preserved left ischium does not show in this view. Diagram illustrates preserved elements only and does not accurately reflect the proportions of CMNFV 22039.

Skeletal drawing modified after original illustrations of Pachycephalosaurus (postcranium) and “Dracorex” (cranium) by Gregory Paul. Used with permission.

Life reconstruction of CMNFV 22039 in an environment typical of the upper Maastrichtian Frenchman Formation. 

Illustration by Kaitlin Lindblad. Used with permission.

 

Bryan R. S. Moore, David C. Evans, Michael J. Ryan, R. Timothy Patterson and Jordan C. Mallon. 2026. The ontogenetically youngest known pachycephalosaur (Dinosauria: Ornithischia) postcranium. Journal of Vertebrate Paleontology. e2616325. DOI: 10.1080/02724634.2026.2616325 [26 Feb 2026]

 www.tandfonline.com/doi/full/10.1080/02724634.2026.2616325

 x.com/Jordan_Mallon/status/2027031604879835644

[PaleoOrnithology • 2025] Consoravis turdirostris • A New Species of Morsoravidae sheds light on Beak and Limb Morphology in stem Passerines

Consoravis turdirostris

Ksepka, Bertelli, Balanoff & Grande, 2025

 DOI: doi.org/10.1080/02724634.2025.2514121 

 x.com/KsepkaLab

ABSTRACT

Morsoravidae is a small clade of probable stem passerines known from the Eocene of Europe and North America. Here, we report an articulated skeleton of a new species of Morsoravidae from the Green River Formation of Wyoming. In contrast to Morsoravis sedilis and Pumiliornis tessellatus, in which the nares appear to have been schizorhinal, the nares of the Consoravis turdirostris gen. et sp. nov. are ovoid and do not extend caudally beyond the nasofrontal hinge. In addition, the processus retroarticularis is much shorter in Consoravis than in Morsoravis. The humerus is similar to that of extant passerines, with a short shaft, short crista deltopectoralis, well-developed tuberculum supracondylare dorsale, and strongly projected processus flexorius. However, the more distal wing elements differ from those of crown passerines in that the olecranon is blunt and the carpometacarpus has a weakly developed processus extensorius. Although fully zygodactyl stem passerines are now well-documented, Consoravis and Sororavis exhibit a semi-zygodactyl foot, in which the trochlea of the fourth metatarsal bears a wing-like flange but lacks a fully developed trochlea accessoria. The unspecialized beak, modest wing length, and relatively short leg together suggest arboreal habits and a generalized diet of invertebrates and fruit for Consoravis, in contrast to more specialized diets of the nectivorous Pumiliornis and the rhynchokinetic, possibly probe-feeding Morsoravis. Phylogenetic analyses support the monophyly of Morsoravidae and weakly support the placement of this clade as sister to all other passerines. These analyses also support the identification of the Oligocene Jamna szybiaki as a stem passerine and the paraphyly of Zygodactylidae.

Consoravis turdirostris gen. et sp. nov. 

Daniel T. Ksepka, Sara Bertelli, Amy M. Balanoff and Lance Grande. 2025. A New Species of Morsoravidae sheds light on Beak and Limb Morphology in stem Passerines. Journal of Vertebrate Paleontology. 45(1);  e2514121. DOI: doi.org/10.1080/02724634.2025.2514121  [03 Jul 2025]

 x.com/KsepkaLab/status/1941183737976455248

[Paleontology • 2025] Thikarisuchus xenodentes • A New, diminutive, heterodont Neosuchian from the Vaughn Member of the Blackleaf Formation (Cenomanian), southwest Montana, and Implications for the Paleoecology of heterodont neosuchians

 

Thikarisuchus xenodentes

Allen, Wilberg, Turner & Varricchio, 2025  

 DOI: doi.org/10.1080/02724634.2025.2542185 

Illustration by Dane Johnson/Museum of the Rockies

ABSTRACT

Although crocodyliforms from the Campanian–Maastrichtian of North America have received considerable attention, taxa occurring earlier in the Cretaceous have only recently begun to be more thoroughly studied. Of particular interest amongst these recent discoveries is the heterodont neosuchian Wannchampsus kirpachi Adams 2014 and the similar, undescribed ‘Glen Rose Form’ (USNM 22039). Both hold an unclear phylogenetic position, either forming a clade sister to Atoposauridae, a group of small, heterodont neosuchians from the Jurassic and Cretaceous of Laurasia, or to Paralligatoridae, a clade of larger, platyrostral, homodont neosuchians from the Cretaceous of Asia and North America. Here we describe a new species of diminutive, heterodont neosuchian, Thikarisuchus xenodentes gen. et sp. nov., from the early–middle Cenomanian Vaughn Member of the Blackleaf Formation of southwest Montana. The specimen includes cranial, mandibular, axial, and appendicular elements in articulation and dense concentration. It is recovered in a sister relationship with Wannchampsus and USNM 22039. We propose the name Wannchampsidae (clade nov.) for this group of small, heterodont neosuchians endemic to the Cretaceous of North America. Wannchampsidae is more confidently recovered sister to Atoposauridae due to the recognition of new synapomorphies. The new taxon provides greater clarity on the potential diet and paleoecology of Wannchampsidae and Atoposauridae and displays similar craniomandibular and dental characteristics to the notosuchian group Uruguaysuchidae, strongly suggesting these neosuchian groups were also omnivorous or insectivorous and terrestrially adapted, respectively representing a unique diet and reversion to terrestriality within Neosuchia.

SYSTEMATIC PALEONTOLOGY

CROCODYLOMORPHA Hay, 1930 (sensu Nesbitt, 2011)

CROCODYLIFORMES Hay, 1930 (sensu Clark, 1986)

NEOSUCHIA Clark in Benton and Clark, 1988

WANNCHAMPSIDAE, family nov.

Type Genus—Wannchampsus kirpachi Adams, 2014.

Etymology—'The family of Wannchampsus.’ The stem Wannchamps- is based on the designated type genus Wannchampsus. -idae, is a Latin patronymic suffix.

Under Article 29.2 of the Zoological Code, the suffix -idae denotes a family rank within the family-group.

Phylogenetic Definition—Branch-based clade comprising all taxa more closely related to Wannchampsus kirpachi Adams, 2014 than to Theriosuchus pusillus Owen, 1878 or Shamosuchus djadochtaensis Mook, 1924.

 Skeletal diagram of preserved elements of Thikarisuchus xenodentes (MOR 11969). Preserved ribs and osteoderms are not shown. Silhouette based off Araripesuchus spp., illustrating the convergence in craniodental characteristics and terrestrial affinities between these distantly related crocodyliform taxa.

THIKARISUCHUS XENODENTES, gen. et sp. nov.

Locality, Horizon, and Age—Vaughn Member of the upper portions of the Blackleaf Formation (early–middle Cenomanian). Material originates from The Mound (BL-9) in the Lima Peaks area of southwest Montana, southeast of the town of Lima, MT and was recovered on the surface in float or was surface screened, sifted, and later identified/recovered within the lab.

Diagnosis—A small neosuchian crocodyliform with the following unique combination of characters (autapomorphies denoted by an asterisk): longitudinal groove on posterior dentary laterally adjacent to dentary toothrow for reception of posterior maxillary teeth*; extreme mesiodistal elongation and low apicobasal height of posterior ‘low crowned’ maxillary and dentary teeth*; development of frontoparietal midline ridge into a symmetric, elongate hexagonal boss at frontal-parietal suture*; extension of lateral angular ridge onto lateral surface of posterior dentary*; oreinirostral snout; anteriorly oriented external nares; small, anteroposteriorly aligned sulcus present posterior to triple junction of sutures of the premaxilla, maxilla, and nasals; orbitonasal sulcus (sensu Turner, 2015) on lateral surface of maxilla; occlusal pit on palatal process of maxilla adjacent to 4th and 5th maxillary teeth; ventral surface of posterolateral portion of palatal process of maxilla possesses a shallow groove that accommodates some posterior dentary teeth; internal choana bounded almost entirely by pterygoids, with palatines contributing to anterior margin; procoelous cervical, dorsal, and caudal vertebrae; humeral head convex, with the center of the humeral head positioned proximally above the rest of the surface; humerus proximal to deltopectoral crest strongly deflected medially at ∼45° compared with humeral shaft; highly reduced postacetabular process of ilium; elongate proximal process on fibula.

Etymology—After “thikari,” the diminutive form of the Greek word “thiki” meaning sheath, referring to the way in which the posterior maxillary teeth ‘sheath’ within the longitudinal groove on the dentary adjacent to the dentary toothrow as well as the diminutive size of the specimen, and “suchus,” from the Latinized form of “soukhos,” Greek for crocodile. After “xeno,” Greek for strange, and “dentes,” Latin for teeth, referring to the strange heterodont dentition and extremely mesiodistally elongate and apicobasally low posterior teeth.

An artistic rendering of Thikarisuchus xenodentes, an extinct crocodyliform from the Cretaceous of Montana.

Illustration by Dane Johnson/Museum of the Rockies

Harrison J. Allen, Eric W. Wilberg, Alan H. Turner and David J. Varricchio. 2025. A New, diminutive, heterodont Neosuchian from the Vaughn Member of the Blackleaf Formation (Cenomanian), southwest Montana, and Implications for the Paleoecology of heterodont neosuchians. Journal of Vertebrate Paleontology. e2542185. DOI: doi.org/10.1080/02724634.2025.2542185 [22 Sep 2025] 

[PaleoMammalogy • 2024] Acarechimys hunikuini • A New Late Miocene stem Octodontoid (Rodentia: Caviomorpha: Octochinchilloi) from the Solimões Formation (Brazil): Paleobiogeographic Implications

 

Acarechimys hunikuini

 Fontoura, Boivin, Marivaux, Antoine, Stutz, Negri, Ribeiro & Kerber, 2024

DOI: doi.org/10.1080/02724634.2024.2382822 

www.UFSM.br  x.com/KerberLeonardo

Artwork by Márcio L. Castro

ABSTRACT

Caviomorphs are the neotropical hystricognathous rodents (Ctenohystrica: Hystricognathi: Caviomorpha). Octodontoidea are today the richest and most speciose clade of caviomorphs. Their fossil record also reveals a wide array of extinct species, including Acarechimys, a taxon with a widespread South American distribution and extensive temporal range. This genus comprises at least five species documented in deposits ranging from the late Oligocene to the Middle Miocene. Here, we report the discovery of a new species of Acarechimys from Upper Miocene deposits of the Envira River (PRE06 outcrop), situated in the Acre State, western Brazilian Amazonia. The new species differs from the other species of the genus in having lower molars with a strong posterior arm of the metaconid, the presence of a mesostylid (usually prominent) and a neomesolophid forwardly directed and connected to the metalophulid I on m1 but not on m2–3, and the absence of posterior arm of the protoconid. This taxon represents the youngest known species of the Acarechimys lineage to date. Its occurrence in Western Amazonia strengthens support for the hypothesis that South American rodent lineages survived longer during the Neogene at low latitudes than in the southern regions of the continent.

Acarechimys hunikuini

Emmanuelle Fontoura, Myriam Boivin, Laurent Marivaux, Pierre-Olivier Antoine, Narla S. Stutz, Francisco Ricardo Negri, Ana Maria Ribeiro and Leonardo Kerber. 2024. A New Late Miocene stem Octodontoid (Rodentia: Caviomorpha: Octochinchilloi) from the Solimões Formation (Brazil): Paleobiogeographic Implications. Journal of Vertebrate Paleontology. 44(1); e2382822. DOI: doi.org/10.1080/02724634.2024.2382822 [23 Aug 2024]

Pesquisadora da UFSM descreve nova espécie de mamífero extinto

Acarechimys hunikuini recebeu esse nome em homenagem a tribo indígena Huni Kuin que vive na região em que o fóssil foi encontrado

https://www.UFSM.br/2024/08/23/pesquisadora-da-ufsm-descreve-nova-especie-de-mamifero-extinto

 x.com/KerberLeonardo/status/1826936584203043251

[PaleoIchthyology • 2025] Sphyragnathus tyche • A New predatory Actinopterygian from the Tournaisian of Nova Scotia provides insight into the Evolution of Actinopterygian Feeding

 

Sphyragnathus tyche

Wilson, Mansky & Anderson, 2025

 DOI: doi.org/10.1080/02724634.2025.2498453

ABSTRACT

The Devonian–Carboniferous transition represents a fundamental shift in vertebrate faunal composition and ocean ecology. Tournaisian-aged outcrops of the Horton Bluff Formation from Blue Beach, Nova Scotia capture this moment and yield a diverse fauna of actinopterygians and other vertebrates. Here, we report an actinopterygian mandible preserved in 3D, representing a new genus and species, Sphyragnathus tyche. This mandible is elongate, deeply curved, and bears a primary dentition of heterodont fangs. Actinopterygian identity is established by the characteristic ornamentation, dentition, and overall mandible construction observed in the specimen. Analysis of the relationship between mandible and body length in Paleozoic actinopterygians establishes S. tyche as a relatively large actinopterygian. Mandible length, curvature, and fang morphology combine to produce a functionally differentiated dentition with distinct regions for prey capture and prey processing. Comparison with modern actinopterygians places S. tyche as a back-fanged macrodont, distinguishing it from front-fanged macrodont actinopterygians of the Late Devonian. This earliest known instance of back-fanged macrodonty in the actinopterygian fossil record provides further evidence of actinopterygian morphological differentiation post-Devonian and implies experimentation in feeding mode. Apparent changes in feeding mode are underscored by analysis of stress distribution across the dentition of Devonian front-fanged macrodont actinopterygians and S. tyche. Although this specimen is compatible with a previous ‘head-first’ model of morphological diversification in early Carboniferous actinopterygians, we argue that a ‘feeding-first’ model is a better fit.

 

  Sphyragnathus tyche sp. nov. 

Conrad D. Wilson, Chris F. Mansky and Jason S. Anderson. 2025. A New predatory Actinopterygian from the Tournaisian of Nova Scotia provides insight into the Evolution of Actinopterygian Feeding. Journal of Vertebrate Paleontology. e2498453. DOI: doi.org/10.1080/02724634.2025.2498453  [18 Jun 2025]

[Paleontology • 2025] The First gravid ichthyosaur from the Hauterivian (Early Cretaceous): a complete Myobradypterygius hauthali von Huene, 1927 excavated from the border of the Tyndall Glacier, Torres del Paine National Park, southernmost Chile

  

Myobradypterygius hauthali von Huene, 1927 

in Pardo-Pérez, Malkowski, Zambrano, Lomax, Martín, Kaluza, Ortíz, Andrés Marín, Villa-Martínez, Yurac, Cáceres, Zegers, Delgado, Scapini, Astete et Maxwell, 2025. 

DOI: doi.org/10.1080/02724634.2024.2445705

  facebook.com/UdeMagallanes 

  facebook.com: Mauricio Alvarez

ABSTRACT

Ichthyosaurs were pelagic marine reptiles with a global distribution through most of the Mesozoic. Cretaceous Ichthyosauria are mostly known from the northern hemisphere, although findings from the southern hemisphere have been reported from Australia, Argentina, Chile, and New Zealand. Despite these findings that have contributed to knowledge of the clade, there is still a dearth of information about the evolution, phylogenetics, and ecology of Cretaceous ichthyosaurs from the Southernmost Pacific margin of Gondwana. A Lower Cretaceous locality next to the Tyndall Glacier, inside Torres del Paine National Park, southernmost Chile, has yielded 87 ichthyosaur skeletons to date. Most of the specimens recorded from this area are complete and articulated, however, they are affected by recent weathering and the constant erosion. Here we describe a complete platypterygiine ichthyosaur, which we provisionally assign to Myobradypterygius hauthali von Huene, 1927. The specimen was excavated from the border of the glacier in Patagonia during March and April 2022 and corresponds to the first complete excavated ichthyosaur from Chile. This specimen additionally preserves gastrointestinal contents and is the only Hauterivian (131 Ma) ichthyosaur documented to date containing the articulated skeleton of a preserved fetus. This research increases the knowledge of the paleobiology of the species. In addition to morphology, it contributes information regarding paleoecology and paleopathology, diet, and reproduction in M. hauthali, a taxon potentially restricted to the Pacific margin of Gondwana.

 

  

 

Judith M. Pardo-Pérez, Matthew Malkowski, Patricio Zambrano, Dean R. Lomax, Cristina Gascó Martín, Jonatan Kaluza, Héctor Ortíz, Andrés Pérez Marín, Rodrigo Villa-Martínez, Marko Yurac, Miguel Cáceres, Aymara Zegers, Javiera Delgado, Francisca Scapini, Catalina Astete and Erin E. Maxwell. 2025. The First gravid ichthyosaur from the Hauterivian (Early Cretaceous): a complete Myobradypterygius hauthali von Huene, 1927 excavated from the border of the Tyndall Glacier, Torres del Paine National Park, southernmost Chile. Journal of Vertebrate Paleontology. e2445705. DOI: doi.org/10.1080/02724634.2024.2445705 [25 Feb 2025]

  facebook.com/UdeMagallanes/posts/1037390385075772

  facebook.com/DeanRLomax/posts/1176590717805230

  facebook.com/MauricioAlvarez904108/posts/9212059438915634

  facebook.com/JonatanKaluza/posts/10161610354016200