Colosteidae
Colosteidae Temporal range:
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Life restoration and size comparation of three members of Colosteidae | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Sarcopterygii |
Clade: | Tetrapodomorpha |
Clade: | Stegocephali |
Family: | †Colosteidae Cope, 1875 |
Type genus | |
†Colosteus Cope, 1871
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Genera | |
Colosteidae is a
).Description
Colosteids had elongated bodies, with an estimated 40 vertebrae, not including the tail. The skull is relatively flat and composed of many separate bones, like that of other stegocephalians. Colosteids lacked
The mandibular fangs were larger than the palatal ones, though those on the palate were still large. Colosteids were unique compared to most stegocephalians in the fact that a pair of palatal fangs were present on the premaxillary bones at the tip of the snout. In conjunction with the forward position of these fangs, the dentary bones of the lower jaw developed a notch on either side near the symphysis (chin). The symphysis itself is formed by a rough area of bone on the left and right dentaries. This rough patch is formed by a complex system of ridges, which have been described as "brassicate" (textured like a cauliflower).[2] Only Megalocephalus is known to share this brassicate patch with colosteids. The mandibles were also unique in the fact that they possessed a single elongated hole along their inner surface, known as an exomeckelian foramen (or a meckelian fenestra). Earlier stegocephalians like Ichthyostega possessed a subtle slit in the mandible, while most later groups had a series of smaller, well-defined holes.[1]
Relationships
The analysis below was conducted by Swartz in 2012, showing the relationship of colosteids with other tetrapodomorphs.[3]
Elpistostegalia |
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References
External links
- "Tetrapoda: Carboniferous Forms. Colosteidae". Palaeos. Archived from the original on October 6, 2022.
- "Museum of Geology & Natural History: Selected Fossils". West Virginia: Geological & Economic Survey. Archived from the original on October 10, 2023.