Showing posts with label Gondwana. Show all posts
Showing posts with label Gondwana. Show all posts

Saturday, August 1, 2026

[Paleontology • 2026] Cicero spectabilis • Aptian archaeoniscid isopod from the Araripe Basin supports Tethyan-linked dispersal into Gondwanan lacustrine systems


Cicero spectabilis 
Lima, Anker, Heads, Pinheiro & Santana, 2026 

Life reconstruction of Cicero spectabilis n. gen. n. sp. in the Aptian lacustrine environment of the Crato Formation, Araripe Basin, Brazil, showing several individuals scavenging on a dead fish (Dastilbe) on the lake floor, surrounded by aquatic vegetation (Notocyamus hydrophobus), fishes and arthropods.  
 Illustration by Maurílio Oliveira (paleoartist, MN/UFRJ).

Abstract
A new genus and species of fossil isopod, Cicero spectabilis n. gen. n. sp. is described from the Early Cretaceous (Aptian) Nova Olinda Member of the Crato Formation, Araripe Sedimentary Basin, Ceará, northeastern Brazil. The holotype, preserved in laminated limestones, represents the first confirmed record of the family Archaeoniscidae within this stratigraphic unit and extends the previously known paleogeographic distribution of archaeoniscid-like isopods into Gondwana lacustrine settings. The new genus is distinguished from other taxa currently referred to Archaeoniscidae—Archaeoniscus, Ferreniscus and Codoisopus, by its broad, ovate body, distinctive antennular subdivision, and a fan-like caudal structure formed by birramous uropods with well-differentiated exopod and endopod, combined with a rounded subrectangular pleotelson bearing a row of posterior setae. The exceptional preservation of C. spectabilis n. gen. n. sp. enables a detailed assessment of functionally relevant characters and supports interpretation of a benthic lifestyle on soft, low-energy substrates. A conservative concept of the family and a combination of body, pleon-pleotelson and antennular features justifies the placement of Cicero n. gen. within this extinct sphaeromatidean lineage. Within this framework, the occurrence C. spectabilis n. gen. n. sp. in a stratified lacustrine system of the Araripe Basin, together with other Mesozoic archaeoniscid-like records, suggest that some lineages currently assigned to Archaeoniscidae were able to colonize a range of non-marine environments during the Early Cretaceous, while also underscoring the need for a comprehensive phylogenetic reassessment of the group.

Keywords: Malacostraca, Sphaeromatidea, Fossil isopod, Crustacean, Santana group, Archaeoniscidae, Crato formation

Holotype of Cicero spectabilis n. gen. n. sp. from the Aptian Nova Olinda Member of the Crato Formation, Araripe Basin, Brazil (MPSC 9701). A, Ventral view of the specimen preserved in laminated limestone. B, Interpretative line drawing highlighting cephalic appendages, pereopods, pleon, pleotelson, and uropods. Scale bars: 2 mm.

Cicero spectabilis n. gen. n. sp.

Life reconstruction of Cicero spectabilis n. gen. n. sp. in the Aptian lacustrine environment of the Crato Formation, Araripe Basin, Brazil, showing several individuals scavenging on a dead fish (Dastilbe) on the lake floor, surrounded by aquatic vegetation (Notocyamus hydrophobus), fishes and arthropods. Coloration and most dorsal features are conjectural and based on extant sphaeromatidean isopods. Illustration by Maurílio Oliveira (paleoartist, MN/UFRJ).


Daniel Lima, Arthur Anker, Sam W. Heads, Allysson P. Pinheiro and William Santana. 2026. Aptian archaeoniscid isopod from the Araripe Basin supports Tethyan-linked dispersal into Gondwanan lacustrine systems. Scientific Reports. 16: 23631. DOI: doi.org/10.1038/s41598-026-59890-0 [19 July 2026]
 

Monday, July 6, 2026

[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. 
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]


Friday, June 12, 2026

[Paleontology • 2026] Gondwananectes osvaldoi • A new Middle Jurassic marine reptile from Gondwana clarifies the origin of Cryptoclidia, the most successful group of plesiosaurs


Gondwananectes osvaldoi
Otero, Acuña, Vargas, Rojas, Ortiz & Aguirrezabala, 2026

 x.com/ThePalAss

Abstract 
Cryptoclidia (Plesiosauria, Plesiosauroidea) was a major clade of marine reptiles that originated during the Jurassic. The early evolution of Cryptoclidia is documented by records of Cryptoclididae from the Middle Jurassic (174.7–165.1 Ma) and onwards in Europe, the Caribbean and South America. However, the origin of Cryptoclidia itself has remained obscure. Only some traits shared with Cryptoclidia are found in the Toarcian (184.2–174.7 Ma) taxa Plesiopterys wildi and Franconiasaurus brevispinus, from southern Europe. Here we describe a small-bodied sub-adult skeleton belonging to a new plesiosaurian taxon from the Middle Jurassic (c. 170 Ma) of the Atacama Desert (former southwestern Gondwana). The new taxon has single-headed ribs in its axial skeleton, and its combination of novel and ancestral features place it as the sister taxon of Cryptoclidia. The lower Bajocian stage, the phylogenetic position of the new taxon, as well as its palaeogeographic occurrence, point to an older origin and dispersal of Cryptoclidia ancestors, reinforcing the notion that an early Caribbean corridor between the Pacific and Tethyan realms was already functional during the Middle Jurassic.

Keywords: marine reptile, plesiosaurian, phylogeny, Middle Jurassic, Gondwana, palaeogeography


Gondwananectes osvaldoi

 
Rodrigo A. Otero, Sergio Soto Acuña, Alexander O. Vargas, Jennyfer Rojas, Héctor Ortiz, Guillermo Aguirrezabala. 2026. A new Middle Jurassic marine reptile from Gondwana clarifies the origin of Cryptoclidia, the most successful group of plesiosaurs. Papers in Palaeontology. DOI: doi.org/10.1002/spp2.70068 [08 March 2026] 
x.com/ThePalAss/status/2031413080001823092

Thursday, June 11, 2026

[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

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]
 

Tuesday, March 10, 2026

[Paleontology • 2026] Tanyka amnicola • An aberrant Stem Tetrapod from the early Permian of Brazil

 

Tanyka amnicola
 Pardo, Marsicano, Smith, Cisneros, Angielczyk, Fröbisch, Kammerer & Richter, 2026
 
Illustration by Vitor Silva

Abstract
Early evolutionary history of tetrapods is typically divided into two major phases: an initial diversification of archaic stem tetrapod groups, and a sudden replacement by temnospondyl amphibians and amniotes following a late Carboniferous dry interval termed the Carboniferous Rainforest Collapse (CRC). However, the degree to which this scenario applies to the early tetrapods of Gondwana is uncertain. Here, we report Tanyka amnicola, gen. et sp. nov., an archaic stem tetrapod from the early Permian of Brazil characterized by strong torsion of the mandibular ramus and a remarkable battery of enlarged denticles on a strongly arched coronoid. The new taxon is assigned to the tetrapod stem based on the presence of a denticulate adsymphyseal and elevated hook-like glenoid surface without a postglenoid area. Phylogenetic analysis shows affinities between this species and stem tetrapods more proximal to the tetrapod crown group, particularly Eucritta and the Laurussian baphetids. This is the second stem tetrapod group known to have survived until the end of the early Permian in Gondwana despite local extirpation in Laurussia, implying that current hypotheses of Carboniferous tetrapod turnover are oversimplified. The unique jaw morphology suggests adaptations to either specialized processing of small invertebrates or consumption of some plant material, demonstrating that stem tetrapods continued to explore new niche space into the Permian of Gondwana.

Keywords: Permian, Tetrapoda, palaeobiogeography

Holotype jaw of Tanyka amnicola, MAP-PV 662.
(a) MAP-PV 662 in dorsal view; (b) interpretive drawing of MAP-PV 662 in dorsal view;
(c) MAP-PV 662 in ventral view; (d) interpretive drawing of MAP-PV 662 in ventral view.
adsym, adsymphyseal; an, angular; ar, articular; c1, first coronoid; c2, second coronoid; c3, third coronoid; ct, foramen for chorda tympani; d, dentary; laf, lateral angular flange; Mf, Meckelian fenestra; par, prearticular; pMf, pre-Meckelian foramina; pspl, postsplenial, sa, surangular; sfp, symphyseal fang pair of dentary; spl, splenial.

Tetrapodamorpha Ahlberg, 1991

Tanyka amnicola gen. et sp. nov.

Holotype. MAP-PV 662, nearly complete left mandible. Accessioned at Museu de Arqueologia e Paleontologia (MAP) at Universidade Federal do Piauí, Teresina, Brazil.

Type locality and horizon. Pedra de Fogo riverbank, MAP locality PB 156, south of Pastos Bons, Maranhão, lower Pedra de Fogo Formation, early Permian.

 
Etymology. Guarani: tañykã, meaning ‘jaw’ or ‘chin’, and Latin: amnicola, meaning ‘living in or next to the river’ the latter being a reference both to the river bed in Pastos Bons where the holotype was found and also to the presumed aquatic habits of the stem tetrapod.

Diagnosis. Stem tetrapod of moderate size. Adsymphyseal and all coronoids covered in a thickly ankylosed and arched denticle pad much wider than the tooth row. Occlusal surface of jaw, including coronoid denticle plate, faces more labially than dorsally when jaw is in neutral position. Ventral margin of jaw ramus wider than dentary-coronoid area. Angular with prominent sculptured flange. Prearticular braces articular medially with a large triangular process. Meckelian foramen small (less than one-third the depth of the prearticular).

Jaw rotation during mandibular adduction in Tanyka.
(a) Jaw in closed position, lateral view; (b) jaw in closed position, anterior view;
(c) jaw in open position, lateral view; (d) jaw in open position, anterior view.
General skull shape speculative, based on Baphetes

Illustration showing Tanyka amnicola in life, eating underwater plants.
 Artwork: Vitor Silva
 

Jason D. Pardo; Claudia A. Marsicano; Roger Smith; Juan Carlos Cisneros; Kenneth D. Angielczyk; Jörg Fröbisch; Christian F. Kammerer; Martha Richter. 2026. An aberrant Stem Tetrapod from the early Permian of Brazil. Proc Biol Sci. 293 (2066): 20252106. DOI: doi.org/10.1098/rspb.2025.2106 [04 Mar 2026]
  

Saturday, November 29, 2025

[Paleontology • 2025] The coelurosaur theropods of the Romualdo Formation, early Cretaceous (Aptian) of Brazil: Santanaraptor placidus meets Mirischia asymmetrica


Hypothetical reconstruction of Mirischia asymmetrica (left) and Santanaraptor placidus (right) disputing a lizard in what is now northeastern Brazil ~112 million years ago (Early Cretaceous, Aptian).

Santanaraptor placidus Kellner, 1999 
Mirischia asymmetrica Naish, Martill & Frey, 2004

in Delcourt, Grillo, Hendrickx, Kellermann et Langer, 2025.
 Santanaraptor   Mirischia 
Illustration by Guilherme Gehr. 
 
Abstract
The upper carbonate concretion levels of the Romualdo Formation (Aptian, Brazil) have yielded several theropod dinosaur remains, including spinosaurids and the coelurosaurs Santanaraptor placidus and Mirischia asymmetrica, the phylogenetic affinities of which are controversial. Here, we present a comprehensive anatomical reassessment of the holotypes of both species (MN 4802-V and SMNK 2349 PAL, respectively), integrating newly observed osteological features and a detailed comparison of the pelvic and hind limb elements. Our preferred phylogenetic hypothesis places S. placidus and M. asymmetrica in the earliest-branching maniraptoromorph clade, along with Juratyrant langhami and Tanycolagreus topwilsoni from the Late Jurassic of Laurasia, suggesting an early diversification of coelurosaurs in that area, followed by Early Cretaceous dispersal events towards Gondwana. The comparative analysis of the two Romualdo taxa refutes their synonymy, given consistent differences in ischial (position and shape of the obturator plate and foramen) and tibial (condylar configuration) morphology. The observed morphological variation in the ischial obturator plate across early coelurosaurs further highlights a significant degree of homoplasy in this structure during the early radiation of the group. This revision underscores the need for additional research to further resolve the early evolutionary history of coelurosaur theropods.

Keywords: Araripe, Coelurosauria, Dinosauria, Gondwana, Theropoda

Hypothetical reconstruction of Mirischia asymmetrica (left) and Santanaraptor placidus (right) disputing a lizard in what is now northeastern Brazil ~112 million years ago (Early Cretaceous, Aptian).
Illustration by Guilherme Gehr. 

Santanaraptor placidus Kellner, 1999
Mirischia asymmetrica Naish, Martill & Frey, 2004

CONCLUSIONS: 
The comprehensive reassessment of Santanaraptor placidus (MN 4802-V) and Mirischia asymmetrica (SMNK 2349) presented here offers new insights into the anatomy, taxonomy, and phylogenetic affinities of these two coelurosaur theropods from the Early Cretaceous (Aptian) Romualdo Formation of Brazil. Despite the minor overlapping of skeletal elements, both specimens exhibit consistent anatomical differences that support their recognition as distinct species. These differences are particularly evident in the configuration of the ischial obturator plate and the structure of the proximal tibial condyles.

Some of our phylogenetic results place S. placidus and M. asymmetrica together with Juratyrant langhami and Tanycolagreus topwilsoni, from the Late Jurassic of Laurasia, in a clade of early branching maniraptoromorphs. This is the first time that these Brazilian taxa are found closely related within a lesser-inclusive clade, corroborating previous assumptions of close biogeographic relations between Laurasian and Gondwanan landmasses by the Early Cretaceous. Further biogeographic patterns are, however, harder to define, especially having in mind the still patchy record of Jurassic theropods in areas such as Africa, Australia, India, Antarctica, and South America.

 
Rafael Delcourt, Orlando Nelson Grillo, Christophe Hendrickx, Maximilian Kellermann, Max Cardoso Langer. 2025. The coelurosaur theropods of the Romualdo Formation, early Cretaceous (Aptian) of Brazil: Santanaraptor placidus meets Mirischia asymmetrica. The Anatomical Record. DOI: doi.org/10.1002/ar.70085 [18 November 2025]

Sunday, November 9, 2025

[PaleoEntomology • 2025] Telmatomyia talbragarica • The Oldest Gondwanan non-biting Midge (Diptera: Chironomidae: Podonominae) sheds light on the Historical Biogeography of the Clade

 

Telmatomyia talbragarica
Baranov, McCurry, Amaral, Beattie & Trewick, 2025

Artwork by Valentyna Inshyna
 
Highlights: 
• This discovery is the oldest Southern Hemisphere record of Chironomidae.
• Podonominae rapidly dispersed from Siberia in Jurassic, or of Gondwana origin.
• Fossil has a unique suction disc—for survival in turbulent environments’.

Abstract
Podonominae, a group of non-biting midges within the Chironomidae family, serves as an important biogeographical model. For a long time, it was believed that Podonominae originated in Northern Gondwana and later spread to Laurasia. However, because the oldest known fossils of this group come from the Jurassic period in Eurasia more recent interpretations have suggested a Laurasian origin.
We present the oldest record of Podonominae from Gondwana, specifically from the Tithonian age (Jurassic) in Australia. This discovery is also the oldest Chironomidae fossil found in the Southern Hemisphere and suggests that Podonominae likely originated in Gondwana. The new fossil represents a highly specialized form of Podonominae, adapted to living in the littoral zones of large lakes. It has adaptations to this environment that are unique amongst Podonominae, and similar to those found in some modern marine Chironomidae species such as Telmatogetoninae.
 
Keywords: Biogeography, Diptera, Podonominae, Jurassic, Gondwana


Systematic palaeontology
Chironomidae (Newman, 1834).
Podonominae Thienemann and Edwards in Thienemann, 1937.

Telmatomyia talbragarica (AM F141771), female pupa.
A) Habitus B) Terminal disk; C) Terminal disk, with enhanced contrast.

Telmatomyia gen. nov.  

Differential diagnosis.
Diagnosis. Pupa: can be distinguished from any other representative of Chironomidae by its very large size (> 9 mm), almost round thoracic horns with plastron occupying about 70 %–80 % of it, and uniquely modified abdominal segments 8 and 9, which form an oval terminal disc with a suture like articulation between the segments, wider than long, apparently without fringe of terminal setae (although there are setae looking marks around the terminal disk.

Etymology: Telmatomyia, is from the Greek “Telmato-” adjective, “of stagnant water” reflecting the lacustrine nature of the habitat at Talbragar, and “myia” – Greek for “fly”.

Telmatomyia talbragarica sp.nov.

Etymology: from Talbragar formation.


 Reconstruction of the lake shore of Talbragar Fossil Fish Bed, depicting several Telmatomyia talbragarica pupae attached to a rock underwater. Pair of Orthogonikleithridae fishes are patrolling the waters of the lake, while Rhoetosaurus brownei is approaching the lakeshore, by the grove of “Agathis” jurassica.
Artwork by Valentyna Inshyna, used with permission.

 
      


Viktor Baranov, Matthew R. McCurry, André P. Amaral, Robert Beattie and Steven A. Trewick. 2025. The Oldest Gondwanan non-biting midge (Diptera, Chironomidae, Podonominae) sheds light on the Historical Biogeography of the Clade. Gondwana Research. DOI: doi.org/10.1016/j.gr.2025.09.001 [8 October 2025]


Friday, August 8, 2025

[PaleoBotany • 2025] Caffapanax canessae & Davidsaralia christophaeOsmoxylon-like Fossils from early Eocene South America: West Gondwana–Malesia Connections in Araliaceae


Caffapanax canessae 
Wilf, 2025
 
Abstract
Premise: Araliaceae comprise a moderately diverse, predominantly tropical angiosperm family with a limited fossil record. Gondwanan history of Araliaceae is hypothesized in the literature, but no fossils have previously been reported from the former supercontinent.

Methods: I describe large (to macrophyll size), palmately compound-lobed leaf fossils and an isolated umbellate infructescence from the early Eocene (52 Ma), late-Gondwanan paleorainforest flora at Laguna del Hunco in Argentine Patagonia.

Results: The leaf fossils are assigned to Caffapanax canessae gen. et sp. nov. (Araliaceae). Comparable living species belong to five genera that are primarily distributed from Malesia to South China. The most similar genus is Osmoxylon, which is centered in east Malesia and includes numerous threatened species. The infructescence is assigned to Davidsaralia christophae gen. et sp. nov. (Araliaceae) and is also comparable to Osmoxylon.

Conclusions: The Caffapanax leaves and Davidsaralia infructescence, potentially representing the same source taxon, are the oldest araliaceous macrofossils and provide direct evidence of Gondwanan history in the family. The new fossils and their large leaves enrich the well-established biogeographic and climatic affinities of the fossil assemblage with imperiled Indo-Pacific, everwet tropical rainforests. The fossils most likely represent shrubs or small trees, adding to the rich record of understory vegetation recovered from Laguna del Hunco.

Keywords: Araliaceae, biogeography, fossil rainforests, Laguna del Hunco, leaf architecture, Malesia, Osmoxylon, paleoconservation, Patagonia

Caffapanax canessae gen. et sp. nov., holotype, MPEF-Pb 10171a (see Figure 2A for counterpart). Specimen has five primary lobes, including a pair of reflexed basal lobes, a pair of lateral lobes each with one sublobe, and an expanded medial lobe with paired sublobes. Scale bar: 10 cm.

Caffapanax canessae gen. et sp. nov., holotype. (A) MPEF-Pb 10171b (counterpart, see Figure 1 for part). Scale bar: 10 cm. (B) Discovery photo with part and counterpart, Laguna del Hunco quarry LH04, 21 November 2006.

Family—Araliaceae Juss.

Genus— Caffapanax Wilf gen. nov.

 Caffapanax canessae Wilf sp. nov.  

Diagnosis—Petiole insertion marginal; base cordate. Blade size microphyll to macrophyll; length:width (L:W) ratio near or below 1:1. Primary veins basally actinodromous, regular, robust. Blade palmately lobed with three or five wide, convex primary lobes; lobe size increases markedly distally. When blade is five-lobed, the basal lobes reflexed, the next lateral lobe pair undivided or with one sublobe per lobe, and the medial lobe much larger than the laterals, with a prominent pair of pinnate sublobes. Margin serrate; teeth short, narrow, non-glandular. Major and minor secondary veins craspedodromous, terminating as tooth principal veins; fimbrial vein present. Higher-order venation well organized; areolation impressed in tiny quadrangular to pentagonal fields; freely ending veinlets absent.

Etymology—The new generic and specific epithets honor Técnicos Mariano Caffa and Leandro Canessa, respectively, of the MEF for their admirable record over more than two decades of fieldwork and fossil discovery in Patagonia. They continue to make significant contributions to paleontology, including the holotype of the new species (Figures 1, 2) unearthed by Téc. Caffa.


Genus—Davidsaralia Wilf gen. nov.
 Davidsaralia christophae Wilf sp. nov. 

 
Peter Wilf. 2025. Osmoxylon-like Fossils from early Eocene South America: West Gondwana–Malesia Connections in Araliaceae. American Journal of Botany. 112(6); e70045. DOI: doi.org/10.1002/ajb2.70045 [19 May 2025]

Sunday, June 1, 2025

[Paleontology • 2025] Itaguyra occulta • Continuous presence of dinosauromorphs in South America throughout the Middle to the Late Triassic

  

 Itaguyra occulta 
 Neto, Pretto, Martinelli, Battista, Garcia, Müller, Schmitt, Melo, Francischini, Schultz, Pinheiro, Soares & Kellner, 2025


Abstract
The dawn of dinosaurs is marked by the appearance of the saurischian lineages in the Late Triassic fossil record, around 230 million years ago. This early burst of diversification of the group is majoritarily represented by sauropodomorphs and herrerasaurids in late Carnian to early Norian of Brazil, Argentina, India, and Zimbabwe. However, “silesaurids”, an older and enigmatic group of quadrupedal dinosauromorphs, were recently found, in some works, as stem ornithischians. In this scenario, dinosaurs would have originated far earlier than the end of the Ladinian, a time in which “silesaurids” are already spread through Gondwana. Despite being also recorded in more recent dinosaur-bearing beds in Brazil, “silesaurids” are absent in strata from the early Carnian, an important time frame for dinosaur evolution. Here we present a new “silesaurid”, Itaguyra occulta gen. et sp. nov., that fills up the remaining gap of occurrence of these dinosauromorphs and provides new clues to the success of these putative early ornithischians.

ARCHOSAURIA Cope, 1869 (sensu Gauthier and Padian, 1985).
AVEMETATARSALIA Gauthier, 1986 (sensu Sereno, 1991).
DINOSAUROMORPHA Benton, 1985 (sensu Ezcurra et al. 2020).

Itaguyra occulta gen. nov. et sp. nov.
 
Etymology: The genus name combines the native Tupi words Ita- (= stone) and -guyra (= bird), referring to the avemetatarsalian nature of the specimen. The specific epithet, derived from Latin, means hidden and refers to the fact that the remains were initially identified as being “mixed up” with other indeterminate cynodont fragments with which they had been collected.


The new “silesaurid” Itaguyra occulta gen. et sp. nov.
 (A) Holotype UFRGS-PV-1365-T. (B) Placement of Rio Grande do Sul State (RS) in Brazil. (C) Exposure of the Santa Maria Supersequence in RS. (D) Locality of the type material (red star) and other correlated localities (pink stars). (E) Restoration of the skeleton (artwork by Maurício Garcia) with known elements in pink.


Holotype: UFRGS-PV-1365(a)-T, a left ilium (Fig. 1A).
Paratype: UFRGS-PV-1365(b)-T, associated ischium (Fig. 1A).

Type and referred locality: The type-materials were collected in the Schoenstatt Sanctuary fossil site (52°27′0.5″ W; 29°44′26.2″ S), in the Santa Cruz do Sul municipality (Fig. 1D), Rio Grande do Sul State, Brazil.

Diagnosis: Itaguyra occulta differs from all other known “silesaurids” with comparable material in (*local autapomorphy): having a faint crest connecting the preacetabular process and the supracetabular crest of the ilium, unlike the prominent ridge of most “silesaurids”*; height of the postacetabular process sub-equal to the height of the acetabulum (shared with Silesaurus opolensis and Kwanasaurus williamparkeri), differing from Lutungutali sitwensis and Gamatavus antiquus (see Discussion); supracetabular crest rounded (shared with Asilisaurus kongwe, Lewisuchus admixtus, Lutungutali sitwensis, and Gamatavus antiquus), unlike the straight outline of Ignotosaurus fragilis, and Kwanasaurus williamparkeri; brevis fossa almost entire visible in lateral view (shared with Silesaurus opolensis Kwanasaurus williamparkeri), being different from Lewisuchus admixtus and Asilisaurus kongwe which are more ventrally oriented; presence of a triangular process continuous to the posterior margin of the brevis fossa (absent in Gamatavus antiquus); triangular ventral margin of the medial wall of the iliac acetabulum (shared with Asilisaurus kongwe, Lutungutali sitwensis, Ignotosaurus fragilis and probably Gamatavus antiquus, but not with Silesaurus opolensis and Kwanasaurus williamparkeri); and, tall shaft of the ischium* (see Discussion).


Worldwide record of “silesaurids” through the Triassic. Paleogeographic maps of the world during the Anisan to Norian, showing the occurrences of ‘silesaurids’.
 Silhouettes not to scale, redrawn from different sources. Silhouettes based on the artwork of Matheus Fernandes Gadelha, Maurício Garcia and Voltaire D. Paes Neto.


 
Voltaire D. Paes Neto, Flávio A. Pretto, Agustín G. Martinelli, Francesco Battista, Maurício Garcia, Rodrigo T. Müller, Mauricio R. Schmitt, Tomaz P. Melo, Heitor Francischini, Cesar L. Schultz, Felipe Pinheiro, Marina B. Soares and Alexander W. Kellner. 2025. Continuous presence of dinosauromorphs in South America throughout the Middle to the Late Triassic. Scientific Reports. 15, 18498.  DOI: doi.org/10.1038/s41598-025-99362-5 [30 May 2025]
 

Thursday, May 8, 2025

[Paleontology • 2025] Rise of the King: Gondwanan Origins and Evolution of Megaraptoran Dinosaurs


Gondwanan Origins and Evolution of Megaraptoran Dinosaurs

in Morrison, Scherer, O’Callaghan, Layton, Boisvert, Rolando, Durrant, Salas, Allain et Gascoigne, 2025. 
 
Abstract
Late Cretaceous Earth was dominated by theropods such as tyrannosauroids and megaraptorans; however, it is unclear how these clades diversified and grew to massive proportions. This study aimed to conduct a biogeographical analysis and test climate as a potential mechanism for the increase in size. We used published phylogenetic matrices with the R package BioGeoBears to test different biogeographical hypotheses for both clades. We mapped body mass (BM) and body length against known climate data to test this potential hypothesis. Continental-scale variance did not drive tyrannosauroid biogeography and instead widespread ancestral populations, sympatric speciation and localized extinctions throughout these clades constricted geographic range. Both patterns were supported by statistical analyses. This biogeographical model also indicates the ancestor of the clade Tarbosaurus and Tyrannosaurus was present in both Asia and Laramidia, and therefore the ancestor of Tyrannosaurus came from Asia. Statistical data illustrated no correlation between Mean Annual Temperature (MAT) and BM but potential climatic shifts may be associated with gigantism in derived megaraptorids and eutyrannosaurians. This biogeographical model implies megaraptorans may have had a cosmopolitan distribution prior to the splitting of Laurasia and Gondwana. Also, gigantism in these clades may be associated with climatic shifts in the Late Cretaceous.

Keywords: Biogeography, Late Cretaceous, Megaraptora, Tyrannosauroidea
 

The end Cretaceous Northern Hemisphere fauna was dominated by Tyrannosaurids (such as Tyrannosaurus rex), hadrosaurs and ceratopsian ornithischian dinosaurs.
Artwork by Pedro Salas and Sergey Krasovskiy.

Potential dispersal routes for megaraptorans during the Middle Jurassic–Early Cretaceous (approx. 143 Ma). ...


Cassius Morrison, Charlie Roger Scherer, Ezekiel V. O’Callaghan, Collin Layton, Colin Boisvert, Mauro Aranciaga Rolando, Leroy Durrant, Pedro Salas, Steven J. R. Allain and Samuel J. L. Gascoigne. 2025. Rise of the King: Gondwanan Origins and Evolution of Megaraptoran Dinosaurs. R. Soc. Open Sci. 12: 242238. DOI: doi.org/10.1098/rsos.242238  [07 May 2025] 
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Thursday, April 10, 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. 

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]
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