[PaleoIchthyology • 2026] New Data on the sarcopterygian Koharalepis jarviki (Tetrapodomorpha: Canowindridae) from the Late Devonian of Antarctica, revealed via Synchrotron and Neutron Tomography

 

Koharalepis jarviki Young & Ritchie, 1992  
3D rendering of Koharalepis jarviki (AMF 54325) from neutron tomographic data.

  in Mensforth, Long, Bevitt et Clement, 2026. 

DOI: doi.org/10.3389/fevo.2026.1765271

Artwork: Thomas Turner

Abstract

Introduction: The ‘osteolepiforms’ are an extinct order of lobe-finned fishes that had a cosmopolitan distribution, which are often considered for their proximity to the vertebrate water-to-land transition. The canowindrids are an East Gondwanan clade of tetrapodomorph fishes that exhibit a high level of endemism. However, due to the rarity of canowindrid material and their taphonomy, there is only a single representative preserved wholly in 3D and thus suitable for investigation via modern non-invasive tomography.

Methods: Here we present an updated description of the holotype of Koharalepis jarviki, a canowindrid collected from the Late Devonian Aztec Siltstone formation in Mt Crean, Antarctica, elucidated via a combination of synchrotron and neutron tomography.

Results and discussion: New elements of the braincase, palate, mandible and axial skeleton are revealed for the first time, and previously reported anatomy including the dermal skull and position of the orbits are confirmed. A partial braincase and endocast has been reconstructed, enabling rare insight into the neural anatomy of Koharalepis. Phylogenetic analysis confirms Koharalepis as a member of the Canowindridae with Harajicadectes zhumini recovered as sister taxon. The canowindrids occupy a region of the phylogenetic tree with ‘osteolepidid’ taxa and megalichthyids, crownward of rhizodonts but below tristichopterids and elpistostegalids. This work provides greater support for the taxonomic characters and phylogenetic position of the enigmatic canowindrid family, and the 3D preservation of this material has enabled us to infer some behavioural and ecological insight.

Keywords: 3D modelling, canowindrid, Devonian, endocast, neutron tomography, phylogenetic analysis, Sarcopterygii, tetrapodomorph

3D rendering of Koharalepis jarviki (AMF 54325) from neutron tomographic data in (A) dorsal view, (B) ventral view, (C) anterior view, (D) left lateral view and (E) posterior view.

Et, extra temporal; Ju, jugal; L.Ex, lateral extrascapular; M.Ex, median extrascapular; Op, operculum; Par, parietal; Po, postorbital; PP, postparietal; Sclm, supracleithrum; Sq, squamosal.

Life reconstruction of the Devonian tetrapodomorph fish Koharalepis jarviki.

Artwork: Thomas Turner/Flinders University

 Koharalepis jarviki Young & Ritchie, 1992

Corinne L. Mensforth, John A. Long, Joseph J. Bevitt and Alice M. Clement. 2026. New Data on the sarcopterygian Koharalepis jarviki (Tetrapodomorpha; Canowindridae) from the Late Devonian of Antarctica, revealed via Synchrotron and Neutron Tomography. Front. Ecol. Evol. (14); DOI: doi.org/10.3389/fevo.2026.1765271 [16 April 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

 

DOI: doi.org/10.1098/rspb.2025.2106

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]

  

[PaleoIchthyology • 2022] Langlieria smalingi • Second Species of Langlieria (Sarcopterygii: Tristichopteridae) from the Upper Devonian Catskill Formation of Pennsylvania, U.S.A., and A New Phylogenetic Consideration of Tristichopteridae

Langlieria smalingi

Downs & Daeschler, 2022

DOI: 10.1635/053.167.0115 

 

Abstract

A new species of Langlieria is described from the Upper Devonian (Frasnian) Irish Valley Member of the Catskill Formation. The type material was collected from a road cut exposure on the north side of the westbound lanes of Pennsylvania Route 322 west of Port Matilda, Centre County, Pennsylvania, U.S.A. The new species of Langlieria, the second from the Catskill Formation, is represented by high quality cranial material including parietal and postparietal shields, cheek, principal gular, and lower jaw; fin material; and body scales. The new species is the fourth tristichopterid to be described from the Catskill Formation (after Hyneria lindae, Langlieria radiatus, and Eusthenodon bourdoni) and the first from the Irish Valley Member. It is also the first species of Langlieria with a known record in the Frasnian. Sedimentological and stratigraphic data suggest that the discovery site represents a distal, tide-dominated location within the Catskill Delta system with a greater marine influence than has been reconstructed for the previously described Catskill Formation tristichopterids. A new phylogenetic analysis of Tristichopteridae is presented that is the first to include the new species of Langlieria described here and E. bourdoni from the Cogan House Exit Ramp locality (Famennian, Duncannon Member) along U.S. Route 15/Interstate 99. The 50% majority-rule consensus tree from the analysis supports a highly-nested clade of tristichopterids that includes all of the considered species from the Famennian, with the exception of Heddleichthys dalgleisiensis, and additionally includes the Frasnian Langlieria species that is described here.

Langlieria smalingi

Jason P. Downs and Edward B. Daeschler. 2022. Second Species of Langlieria (Tristichopteridae, Sarcopterygii) from the Upper Devonian Catskill Formation of Pennsylvania, U.S.A., and A New Phylogenetic Consideration of Tristichopteridae. Proceedings of the Academy of Natural Sciences of Philadelphia. 167(1); 241-260. DOI: 10.1635/053.167.0115 

 

NEW SPECIES OF ANCIENT FISH DISCOVERED ALONG PENNSYLVANIA ROADSIDE

newsblog.drexel.edu/2022/04/26/new-species-of-ancient-fish-discovered-along-pennsylvania-roadside/

[Paleontology • 2024] Gaiasia jennyae • Giant stem Tetrapod was Apex Predator in Gondwanan late Palaeozoic Ice Age

  

Gaiasia jennyae

Marsicano, Pardo, Smith, Mancuso, Gaetano & Mocke, 2024

DOI: 10.1038/s41586-024-07572-0

Abstract

Current hypotheses of early tetrapod evolution posit close ecological and biogeographic ties to the extensive coal-producing wetlands of the Carboniferous palaeoequator with rapid replacement of archaic tetrapod groups by relatives of modern amniotes and lissamphibians in the late Carboniferous (about 307 million years ago). These hypotheses draw on a tetrapod fossil record that is almost entirely restricted to palaeoequatorial Pangea (Laurussia). Here we describe a new giant stem tetrapod, Gaiasia jennyae, from high-palaeolatitude (about 55° S) early Permian-aged (about 280 million years ago) deposits in Namibia that challenges this scenario. Gaiasia is represented by several large, semi-articulated skeletons characterized by a weakly ossified skull with a loosely articulated palate dominated by a broad diamond-shaped parasphenoid, a posteriorly projecting occiput, and enlarged, interlocking dentary and coronoid fangs. Phylogenetic analysis resolves Gaiasia within the tetrapod stem group as the sister taxon of the Carboniferous Colosteidae from Euramerica. Gaiasia is larger than all previously described digited stem tetrapods and provides evidence that continental tetrapods were well established in the cold-temperate latitudes of Gondwana during the final phases of the Carboniferous–Permian deglaciation. This points to a more global distribution of continental tetrapods during the Carboniferous–Permian transition and indicates that previous hypotheses of global tetrapod faunal turnover and dispersal at this time must be reconsidered.

 

Claudia A. Marsicano, Jason D. Pardo, Roger M. H. Smith, Adriana C. Mancuso, Leandro C. Gaetano  and Helke Mocke. 2024. Giant stem Tetrapod was Apex Predator in Gondwanan late Palaeozoic ice age. Nature.  DOI: 10.1038/s41586-024-07572-0

[PaleoIchthyology • 2023] Hyneria udlezinye • A high Latitude Gondwanan Species of the Late Devonian tristichopterid Hyneria (Osteichthyes: Sarcopterygii) from South Africa

 

 Hyneria udlezinye

Gess & Ahlberg, 2023

DOI: 10.1371/journal.pone.0281333

Painting by Maggie Newman

Abstract

We describe the largest bony fish in the Late Devonian (late Famennian) fossil assemblage from Waterloo Farm near Makhanda/Grahamstown, South Africa. It is a giant member of the extinct clade Tristichopteridae (Sarcopterygii: Tetrapodomorpha) and most closely resembles Hyneria lindae from the late Famennian Catskill Formation of Pennsylvania, USA. Notwithstanding the overall similarity, it can be distinguished from H. lindae on a number of morphological points and is accordingly described as a new species, Hyneria udlezinye sp. nov. The preserved material comprises most of the dermal skull, lower jaw, gill cover and shoulder girdle. The cranial endoskeleton appears to have been unossified and is not preserved, apart from a fragment of the hyoid arch adhering to a subopercular, but the postcranial endoskeleton is represented by an ulnare, some semi-articulated neural spines, and the basal plate of a median fin. The discovery of H. udlezinye shows that Hyneria is a cosmopolitan genus extending into the high latitudes of Gondwana, not a Euramerican endemic. It supports the contention that the derived clade of giant tristichopterids, which alongside Hyneria includes such genera as Eusthenodon, Edenopteron and Mandageria, originated in Gondwana.

Systematic palaeontology

OSTEICHTHYES Huxley, 1880

SARCOPTERYGII Romer, 1955

TETRAPODOMORPHA Ahlberg, 1989

TRISTICHOPTERIDAE Cope, 1889

Diagnosis— Tetrapodomorph sarcopterygians with postspiracular bone present, vomers with long caudal process clasping the parasphenoid, circular scales with a median boss, and an elongate body with a trifurcate or rhombic caudal fin (modified from [3]).

HYNERIA Thomson, 1968

Type species— Hyneria lindae Thomson, 1968; Hyner, Pennsylvania, USA.

AM6540b and AM6528a, the two main blocks of the holotype of Hyneria udlezinye.
Each block also has a counterpart (not illustrated). A, AM6540b. Unlabelled bones all belong to a single large individual of the arthrodire placoderm Groenlandaspis riniensis [Long, et al. 1997]. B, AM6528a. This block also carries a jugal of the tetrapod Umzantsia amazana [Gess & Ahlberg, 2018] and a paranuchal of a small individual of Groenlandaspis riniensis.

Skull reconstruction of Hyneria udlezinye.
Dorsal (A) and lateral (B) views, drawn from photographs of a three-dimensional model, scaled to the size of the holotype.

Abbreviations: An, anocleithrum; Ang, angular; Cl, clavicle; Cle, cleithrum; De, dentary; It, intertemporal; Ju, jugal; La, lacrimal; M.Pr, median postrostral; Mx, maxilla; Op, opercular; Pa, parietal; Pi, pineal; Po, postorbital; Pop, preopercular; Pospl, postsplenial; Pp-St-Ta, postparietal, supratemporal and tabular (sutures not visible); Qj, qudratojugal; Sop, subopercular; Sq, squamosal; Sur, surangular.

Hyneria udlezinye sp. nov.  

"Probable eusthenopterid" [Gess & Hiller, 1995]

"Close to Eusthenodon" [Anderson, et al., 1999]

"Similar to Hyneria" [Gess & Coates, 2008]

"cf Hyneria" [Gess, 2011]

"Hyneria-like" [Gess & Whitfield, 2020]

Diagnosis—A very large tristichopterid, closely resembling Hyneria lindae but differing from it in the following respects: postparietal shield widening more strongly from anterior to posterior; lateral corner of tabular weakly developed; preopercular and lacrimal proportionally deeper; denticulated field on parasphenoid extends further anteriorly; subopercular more shallow; dentary fangs proportionately larger.

Etymology— an apposition, from isiXhosa ‘udlezinye’, meaning ‘one who eats others’, referring to the inferred predatory lifestyle of the species. IsiXhosa is the widely spoken indigenous language of south-eastern South Africa where the fossil locality is located.

Life reconstruction of the non-marine component of the Waterloo Farm biota. Hyneria udlezinye is shown together with the tetrapods Umzantsia amazana and Tutusius umlambo [Gess & Ahlberg, 2018], the placoderms Groenlandaspis riniensis and Bothriolepis africana [Long, et al., 1997], the coelacanth Serenichthys kowiensis [Gess & Coates, 2015], the lungfish Isityumzi mlomomde [Gess & Clemen, 2019], and a cyrtoctenid eurypterid.

Painting by Maggie Newman, copyright R. W. Gess.

Conclusion: 

The largest osteichthyan member of the Waterloo Farm vertebrate assemblage, a predatory sarcopterygian with a probable maximum length of nearly three metres, proves to be a new species of the genus Hyneria. This genus is otherwise only recorded from the late Famennian Catskill Formation of Pennsylvania. The new species, Hyneria udlezinye, differs from the type species Hyneria lindae in a number of minor but securely attested proportional characters relating to the skull roof, cheek, lower jaw and operculum. Hyneria now joins Eusthenodon and Langlieria as one of the derived, late, giant tristichopterids known from both Euramerica and Gondwana. The other confirmed members of this clade (Mandageria, Cabonnichthys and Edenopteron) are exclusively known from Gondwana. This strongly supports the contention that this clade represents a Gondwanan radiation [Olive, et al. 2020].

Hyneria udlezinye is the first tristichopterid to be recorded from a high palaeolatitude, all other members of the group coming from palaeoequatorial to mid-palaeolatitude localities. All previously recorded Gondwanan members of the derived tristichopterid clade come from Australia, leading Olive et al. [2020] to argue for an Australian origin for this clade. The new evidence from Waterloo Farm, however, suggests that a more general Gondwanan origin for this clade is highly likely. This once again demonstrates how inferences about biogeographical patterns have historically been skewed by a paucity of data from high-palaeolatitude localities. Such data can only come from Gondwana, as no continents extended into northern high latitudes during the Devonian. The Waterloo Farm lagerstätte provides a unique window into an almost unknown part of the Late Devonian world.

Robert W. Gess and Per E. Ahlberg. 2023. A high Latitude Gondwanan Species of the Late Devonian tristichopterid Hyneria (Osteichthyes: Sarcopterygii). PLoS ONE. 18(2): e0281333. DOI: 10.1371/journal.pone.0281333

[Paleontology • 2022] Qikiqtania wakei • A New Elpistostegalian (Sarcopterygii: Tetrapodomorpha) from the Late Devonian of the Canadian Arctic

Qikiqtania wakei

 Stewart, Lemberg, Daly, Daeschler & Shubin, 2022

DOI: 10.1038/s41586-022-04990-w

Abstract

A fundamental gap in the study of the origin of limbed vertebrates lies in understanding the morphological and functional diversity of their closest relatives. Whereas analyses of the elpistostegalians Panderichthys rhombolepis, Tiktaalik roseae and Elpistostege watsoni have revealed a sequence of changes in locomotor, feeding and respiratory structures during the transition, an isolated bone, a putative humerus, has controversially hinted at a wider range in form and function than now recognized. Here we report the discovery of a new elpistostegalian from the Late Devonian period of the Canadian Arctic that shows surprising disparity in the group. The specimen includes partial upper and lower jaws, pharyngeal elements, a pectoral fin and scalation. This new genus is phylogenetically proximate to T. roseae and E. watsoni but evinces notable differences from both taxa and, indeed, other described tetrapodomorphs. Lacking processes, joint orientations and muscle scars indicative of appendage-based support on a hard substrate, its pectoral fin shows specializations for swimming that are unlike those known from other sarcopterygians. This unexpected morphological and functional diversity represents a previously hidden ecological expansion, a secondary return to open water, near the origin of limbed vertebrates.

Systematic palaeontology

Sarcopterygii Romer, 1955

Tetrapodomorpha Ahlberg, 1991

Elpistostegalia Camp and Allison, 1961

Qikiqtania wakei gen. et sp. nov.

Locality. Canada, Nunavut, southern Ellesmere Island, near the eastern arm of Bird Fiord, Nunavut Paleontological Expedition site NV0401, ....

Geological setting. Fram Formation (Upper Devonian, early Frasnian Stage).

Holotype. Nunavut Fossil Vertebrate Collection (NUFV) 137.

 

Diagnosis. Elpistostegalian tetrapodomorph characterized by the following unique combination of characters: dorsoventral asymmetry in pectoral fin lepidotrichia (also present in T. roseae) and possession of a boomerang-shaped humerus lacking ventral ridge and associated foramina and ectepicondyle (distinct from P. rhombolepis, E. watsoni, T. roseae and more crownward tetrapods).

Etymology. Qikiqtania (pronounced ‘kick-kiq-tani-ahh’) is derived from Inuktitut word Qikiqtaaluk/Qikiqtani, the traditional name for the region where the fossil site occurs. The species designation is in memory of David Wake, an eminent evolutionary biologist and transformative mentor, late of the University of California at Berkeley.

 

Thomas A. Stewart, Justin B. Lemberg, Ailis Daly, Edward B. Daeschler and Neil H. Shubin. 2022. A New Elpistostegalian from the Late Devonian of the Canadian Arctic. Nature. DOI: 10.1038/s41586-022-04990-w

    

[PaleoIchthyology • 2017] Hongyu chowi • A Devonian Tetrapod-like Fish Reveals Substantial Parallelism in Stem Tetrapod Evolution

Hongyu chowi 

Zhu, Ahlberg, Zhao & Jia, 2017  

DOI: 10.1038/s41559-017-0293-5 

Abstract

The fossils assigned to the tetrapod stem group document the evolution of terrestrial vertebrates from lobe-finned fishes. During the past 18 years the phylogenetic structure of this stem group has remained remarkably stable, even when accommodating new discoveries such as the earliest known stem tetrapod Tungsenia and the elpistostegid (fish–tetrapod intermediate) Tiktaalik. Here we present a large lobe-finned fish from the Late Devonian period of China that disrupts this stability. It combines characteristics of rhizodont fishes (supposedly a basal branch in the stem group, distant from tetrapods) with derived elpistostegid-like and tetrapod-like characters. This mélange of characters may reflect either detailed convergence between rhizodonts and elpistostegids plus tetrapods, under a phylogenetic scenario deduced from Bayesian inference analysis, or a previously unrecognized close relationship between these groups, as supported by maximum parsimony analysis. In either case, the overall result reveals a substantial increase in homoplasy in the tetrapod stem group. It also suggests that ecological diversity and biogeographical provinciality in the tetrapod stem group have been underestimated.

Fig. 1 | V17681, holotype of Hongyu chowi gen. et sp. nov. ; Dorsal view. 

Systematic palaeontology. 

Osteichthyes Huxley, 1880

Sarcopterygii Romer, 1955

Tetrapodomorpha Ahlberg, 1991

Hongyu chowi gen. et sp. nov.

Etymology. The generic name derives from hong (Chinese Pinyin), which means large and yu (Chinese Pinyin), which means fish. The specific is in honor of Min-Chen Chow. 

Holotype. IVPP V17681, a three-dimensionally preserved and partially articulated specimen.

 Locality. A quarry at Shixiagou, Qingtongxia, Ningxia, China. Approximate coordinates: 37° 39′ 18.4″ N, 105° 59′ 34.2″ E. Horizon. Zhongning Formation, Famennian, Late Devonian period.

Fig. 4 | Life restoration. Hongyu chowi gen. et sp. nov. and associated antiarchs (Ningxialepis spinosa) from the Zhongning Formation (Famennian, Late Devonian period), Ningxia, China.

Illustration: B. Choo.

Min Zhu, Per E. Ahlberg, Wen-Jin Zhao and Lian-Tao Jia. 2017. A Devonian Tetrapod-like Fish Reveals Substantial Parallelism in Stem Tetrapod Evolution.

 Nature Ecology & Evolution. DOI: 10.1038/s41559-017-0293-5

Weird fish fossil changes the story of how we moved onto land

newscientist.com/article/2146256-weird-fish-fossil-changes-the-story-of-how-we-moved-onto-land/