Njalila, new gorgonopsian genus from Permian of Tanzania + Gerrothorax postcranial morphology + tetrapod tracks from Pennsylvanian of Czechia
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Ben Creisler
Jan 9, 2026, 1:54:30 PM (yesterday) Jan 9
to DinosaurMa...@googlegroups.com
Ben Creisler
New tetrapod papers:
Njalila gen. nov. for “Dixeya” nasuta
Eva V. I. Gebauer & Michael W. Maisch (2026)
Njalila gen. nov. (Therapsida. Gorgonopsia): a new genus for Dixeya nasuta v. Huene, 1950 from the Late Permian Usili Formation of the Ruhuhu Basin, SW Tanzania
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen (advance online publication)
DOI: 10.1127/njgpa/1296
https://www.schweizerbart.de/papers/njgpa/detail/prepub/107581/Njalila_gen_nov_Therapsida_Gorgonopsia__a_new_genu
urn:lsid:zoobank.org:pub:F4103A77-078E-4F14-87F4-95D76791D5B3
The gorgonopsian genus Njalila gen. nov. (Therapsida, Gorgonopsia) from the Late Permian Usili Formation of the Ruhuhu Basin in southwestern Tanzania is erected for the reception of the species Dixeya nasuta v. Huene, 1950. Njalila is diagnosed on the basis of multiple cranial features, including several autapomorphies, such as the tip of snout pointing dorsally, the septomaxilla bulged anteriorly while forming the lateral margin of the external naris, the dorsal skull roof deeply concave between the orbits with prefrontal short and situated on a marked elevation, and the palate with a ‘pre-fossa’ anterior to the fossa between the palatal tuberosities. A review of the research history on the specimens attributable to Njalila and a discussion on their status is provided, as is a discussion of the status of the original type species of Dixeya, D. quadrata Haughton, 1927. It is concluded that D. quadrata is not congeneric with D. nasuta. It can presently only be considered Gorgonopsia incertae sedis, but may have closer relationships to the genus Lycaenops than envisaged by previous authors. All the remaining ‘Dixeya’-material, currently identified as Arctognathus? nasuta and cf. Arctognathus? nasuta, from the Usili Formation of Tanzania, is attributed to a single species, Njalila nasuta. A single specimen, originally described as a representative of the South African taxon Scylacops capensis, shows some morphological divergence from the remaining specimens, but clearly represents Njalila. It is cautiously determined as Njalila cf. nasuta. Njalila and Arctognathus are compared in detail, and differences that suggest generic separation are recorded. Phylogenetic analysis shows Njalila to be a moderately derived member of the ‘African clade’ of gorgonopsians. A potential sister-group relationship to Arctognathus is indicated, but weakly supported by the currently available data.
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Florian Witzmann and Rainer R Schoch (2026)
Postcranial morphology and ontogeny of the Middle Triassic plagiosaurid temnospondyl Gerrothorax pulcherrimus and the increased body-flattening of bottom-dwelling plagiosaurs
Zoological Journal of the Linnean Society 206(1): zlaf195
doi: https://doi.org/10.1093/zoolinnean/zlaf195
https://academic.oup.com/zoolinnean/article-abstract/206/1/zlaf195/8417649
In order to understand the evolutionary modifications of the skeleton in plagiosaurids, a group of highly aberrant, flattened Triassic temnospondyls, a comprehensive morphological and ontogenetic description of the postcranium of the Middle to Late Triassic plagiosaurid Gerrothorax pulcherrimus (Fraas, 1913) is provided. Character evolution towards and within plagiosaurids involved (i) increasing size and bone thickness of the dermal pectoral girdle, (ii) broadening of the trunk, and (iii) successive flattening of the entire body, correlating with the reduced curvature of the ribs, flattening of the scapula and cleithrum as well as of the ilium and puboischium. The humerus and femur were small but well differentiated. The forelimbs probably served to thrust the anterior body away from the ground especially during the feeding strike, whereas the low caudal neural and haemal arches do not suggest a deep tail fin. Although the complete body was covered by dermal armour, some flexibility between the osteoderms allowed for a certain degree of mobility. Its body proportions indicate that G. pulcherrimus was not a particularly able swimmer and its extreme degree of body flattening suggests a rather passive lifestyle as an ambush predator. It inhabited oligohaline to miohaline water bodies where it preferred oxygen-rich littoral environments.
===
Eva V. I. Gebauer & Michael W. Maisch (2026)
Njalila gen. nov. (Therapsida. Gorgonopsia): a new genus for Dixeya nasuta v. Huene, 1950 from the Late Permian Usili Formation of the Ruhuhu Basin, SW Tanzania
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen (advance online publication)
DOI: 10.1127/njgpa/1296
https://www.schweizerbart.de/papers/njgpa/detail/prepub/107581/Njalila_gen_nov_Therapsida_Gorgonopsia__a_new_genu
urn:lsid:zoobank.org:pub:F4103A77-078E-4F14-87F4-95D76791D5B3
The gorgonopsian genus Njalila gen. nov. (Therapsida, Gorgonopsia) from the Late Permian Usili Formation of the Ruhuhu Basin in southwestern Tanzania is erected for the reception of the species Dixeya nasuta v. Huene, 1950. Njalila is diagnosed on the basis of multiple cranial features, including several autapomorphies, such as the tip of snout pointing dorsally, the septomaxilla bulged anteriorly while forming the lateral margin of the external naris, the dorsal skull roof deeply concave between the orbits with prefrontal short and situated on a marked elevation, and the palate with a ‘pre-fossa’ anterior to the fossa between the palatal tuberosities. A review of the research history on the specimens attributable to Njalila and a discussion on their status is provided, as is a discussion of the status of the original type species of Dixeya, D. quadrata Haughton, 1927. It is concluded that D. quadrata is not congeneric with D. nasuta. It can presently only be considered Gorgonopsia incertae sedis, but may have closer relationships to the genus Lycaenops than envisaged by previous authors. All the remaining ‘Dixeya’-material, currently identified as Arctognathus? nasuta and cf. Arctognathus? nasuta, from the Usili Formation of Tanzania, is attributed to a single species, Njalila nasuta. A single specimen, originally described as a representative of the South African taxon Scylacops capensis, shows some morphological divergence from the remaining specimens, but clearly represents Njalila. It is cautiously determined as Njalila cf. nasuta. Njalila and Arctognathus are compared in detail, and differences that suggest generic separation are recorded. Phylogenetic analysis shows Njalila to be a moderately derived member of the ‘African clade’ of gorgonopsians. A potential sister-group relationship to Arctognathus is indicated, but weakly supported by the currently available data.
====
Florian Witzmann and Rainer R Schoch (2026)
Postcranial morphology and ontogeny of the Middle Triassic plagiosaurid temnospondyl Gerrothorax pulcherrimus and the increased body-flattening of bottom-dwelling plagiosaurs
Zoological Journal of the Linnean Society 206(1): zlaf195
doi: https://doi.org/10.1093/zoolinnean/zlaf195
https://academic.oup.com/zoolinnean/article-abstract/206/1/zlaf195/8417649
In order to understand the evolutionary modifications of the skeleton in plagiosaurids, a group of highly aberrant, flattened Triassic temnospondyls, a comprehensive morphological and ontogenetic description of the postcranium of the Middle to Late Triassic plagiosaurid Gerrothorax pulcherrimus (Fraas, 1913) is provided. Character evolution towards and within plagiosaurids involved (i) increasing size and bone thickness of the dermal pectoral girdle, (ii) broadening of the trunk, and (iii) successive flattening of the entire body, correlating with the reduced curvature of the ribs, flattening of the scapula and cleithrum as well as of the ilium and puboischium. The humerus and femur were small but well differentiated. The forelimbs probably served to thrust the anterior body away from the ground especially during the feeding strike, whereas the low caudal neural and haemal arches do not suggest a deep tail fin. Although the complete body was covered by dermal armour, some flexibility between the osteoderms allowed for a certain degree of mobility. Its body proportions indicate that G. pulcherrimus was not a particularly able swimmer and its extreme degree of body flattening suggests a rather passive lifestyle as an ambush predator. It inhabited oligohaline to miohaline water bodies where it preferred oxygen-rich littoral environments.
===
Free pdf:
Gabriela Calábková, Jakub Březina & Roland Nádaskay (2026)
A highly diverse Pennsylvanian tetrapod ichnoassemblage from the Semily Formation (Krkonoše Piedmont Basin, Czechia)
PeerJ 14:e20437
doi: https://doi.org/10.7717/peerj.20437
The Krkonoše Piedmont Basin (KPB) is one of the Late Paleozoic continental basins in Bohemia, Czechia, comprising a sedimentary sequence from the Late Pennsylvanian to the early Cisuralian. The Pennsylvanian in the KPB consists of alluvial-fluvial to lacustrine deposits with a relatively rich fossil record, comprising mainly ray-finned fishes, freshwater sharks, and invertebrates. Although no skeletal remains of terrestrial vertebrates have been discovered in the Late Pennsylvanian deposits of the KPB, recent studies of tetrapod footprints provide the first direct evidence of pre-Permian terrestrial tetrapod diversity within this basin. A diverse ichnofossil assemblage is represented by six ichnogenera, Amphisauropus, Batrachichnus, Dimetropus, Dromopus, Ichniotherium and Limnopus, including five known ichnospecies, Amphisauropus kablikae, Batrachichnus salamandroides, Dromopus lacertoides, Ichniotherium cottae, and Limnopus heterodactylus, and two unknown ichnospecies, Dimetropus isp. and Limnopus isp. This tetrapod ichnoassemblage is among the most diverse in the Pennsylvanian. Moreover, the Amphisauropus tracks from the KPB represent the first undisputed occurrence of this ichnotaxon in the Gzhelian. Furthermore, the Ichniotherium cottae tracks described here complement the still rare Pennsylvanian occurrences of this ichnospecies in the European part of Pangaea. The ichnofauna studied herein is associated with alluvial-plain to lacustrine nearshore deposits, highlighting the ecological importance of the lacustrine environment and its adjacent areas for the presence of terrestrial vertebrates and the preservation of their footprints.
Gabriela Calábková, Jakub Březina & Roland Nádaskay (2026)
A highly diverse Pennsylvanian tetrapod ichnoassemblage from the Semily Formation (Krkonoše Piedmont Basin, Czechia)
PeerJ 14:e20437
doi: https://doi.org/10.7717/peerj.20437
The Krkonoše Piedmont Basin (KPB) is one of the Late Paleozoic continental basins in Bohemia, Czechia, comprising a sedimentary sequence from the Late Pennsylvanian to the early Cisuralian. The Pennsylvanian in the KPB consists of alluvial-fluvial to lacustrine deposits with a relatively rich fossil record, comprising mainly ray-finned fishes, freshwater sharks, and invertebrates. Although no skeletal remains of terrestrial vertebrates have been discovered in the Late Pennsylvanian deposits of the KPB, recent studies of tetrapod footprints provide the first direct evidence of pre-Permian terrestrial tetrapod diversity within this basin. A diverse ichnofossil assemblage is represented by six ichnogenera, Amphisauropus, Batrachichnus, Dimetropus, Dromopus, Ichniotherium and Limnopus, including five known ichnospecies, Amphisauropus kablikae, Batrachichnus salamandroides, Dromopus lacertoides, Ichniotherium cottae, and Limnopus heterodactylus, and two unknown ichnospecies, Dimetropus isp. and Limnopus isp. This tetrapod ichnoassemblage is among the most diverse in the Pennsylvanian. Moreover, the Amphisauropus tracks from the KPB represent the first undisputed occurrence of this ichnotaxon in the Gzhelian. Furthermore, the Ichniotherium cottae tracks described here complement the still rare Pennsylvanian occurrences of this ichnospecies in the European part of Pangaea. The ichnofauna studied herein is associated with alluvial-plain to lacustrine nearshore deposits, highlighting the ecological importance of the lacustrine environment and its adjacent areas for the presence of terrestrial vertebrates and the preservation of their footprints.
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