Brittagnathus is an extinct genus of four-limbed vertebrate ("tetrapod") from the Late Devonian of Greenland. It contains a single species, Brittagnathus minutus, which is based on a complete lower jaw recovered from an Acanthostega bonebed in the Britta Dal Formation. It is the fourth named genus of "tetrapod" (more precisely a stem-tetrapod or stegocephalian) from the Late Devonian of Greenland, after Ichthyostega, Acanthostega, and Ymeria.[1]

Brittagnathus
Temporal range: late Famennian
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Sarcopterygii
Clade: Tetrapodomorpha
Clade: Stegocephali
Genus: Brittagnathus
Ahlberg & Clack, 2020
Type species
Brittagnathus minutus
Ahlberg & Clack, 2020

The jaw is only 4.5 cm (1.8 in.) long, making Brittagnathus the smallest known Devonian "tetrapod". A phylogenetic analysis places it among Carboniferous stegocephalians, particularly the small whatcheeriid Pederpes, rather than the contemporary Devonian stem-tetrapods. This provides support for an origin for Carboniferous-type tetrapods as early as the Devonian.[1]

References

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  1. ^ a b Ahlberg, Per E.; Clack, Jennifer A. (2020). "The smallest known Devonian tetrapod shows unexpectedly derived features". Royal Society Open Science. 7 (4): 192117. Bibcode:2020RSOS....792117A. doi:10.1098/rsos.192117. PMC 7211834. PMID 32431888.