A chroniosuchid from the Triassic of Kyrgyzstan and analysis of chroniosuchian relationships

2010/10/26 by Rainer R. Schoch, Sebastian Voigt, Michael Buchwitz · 5 citations
Earth and Planetary Sciences · Environmental Science · #Paleontology and Evolutionary Biology #Evolution and Paleontology Studies #Ichthyology and Marine Biology

paper · doi:10.1111/j.1096-3642.2009.00613.x

openalex publication_date 2010/10/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

A nearly complete skull and associated osteoderms from the Middle/Upper Triassic Madygen Formation of Kyrgyzstan are referred to a new chroniosuchid genus and species. The new taxon is characterized by a parabolic skull outline, pustular ornamentation, tabular-squamosal contact, marked postparietal embayments, and the lack of an antorbital fontanelle. The palate is only preserved in part, showing broad palatines and ectopterygoids. Presence of a preorbital fenestra and characteristic osteoderm morphology are synapomorphies shared with all other chroniosuchids. According to the phylogenetic analysis performed, the new chroniosuchid nests with Chroniosaurus, with which it shares the wide, transversely extended osteoderms and pustular ornamentation. The chroniosuchians are robustly supported as a natural group, but their position within the reptiliomorph (stem-amniote) clade is not adequately understood. Whereas the parasphenoid is similar to that of anthracosaurs, most other characters support a higher nesting of chroniosuchians within the stem-amniotes.

Citations

• The skull and skeleton of Eogyrinus attheyi Watson (Amphibia: Labyrinthodontia)
• The Scottish Carboniferous tetrapodCrassigyrinus scoticus(Lydekker)—cranial anatomy and relationships
• The Carboniferous amphibian Proterogyrinus Scheelei Romer, and the early evolution of tetrapods
• A new baphetid (stem tetrapod) from the Upper Carboniferous of Tyne and Wear, U.K., and the evolution of the tetrapod occiput
• The cranial anatomy of two coal measure Anthracosaurs
• On the amphibian Crassigyrinus scoticus watson from the carboniferous
• A review of Silvanerpeton miripedes, a stem amniote from the Lower Carboniferous of East Kirkton, West Lothian, Scotland
• The morphology and relationships of the Carboniferous amphibian Eoherpeton watsoni Panchen
• On Anthracosaurus Russelli Huxley (Amphibia: Labyrinthodontia) and the family Anthracosauridae
• Early tetrapod relationships revisited

Cited by

• Kyrgyzsaurus bukhanchenkoi gen. et sp. nov., a new reptile from the triassic of southwestern Kyrgyzstan
• Late Triassic Terrestrial Tetrapods: Biostratigraphy, Biochronology and Biotic Events
• Phylogeny of Paleozoic limbed vertebrates reassessed through revision and expansion of the largest published relevant data matrix
• The youngest occurrence of embolomeres (Tetrapoda: Anthracosauria) from the Sunjiagou Formation (Lopingian, Permian) of North China
• Madygen Formation [wikipedia]