Genesis of snakes in exodus from the sea
Article Abstract:
Paleontologists are trying to determine the origins of snakes by examining fossil records. The records show that snakes (Ophidia) are descendants of the order Squamata (scaly reptiles). However, the crux of the matter is what division of the order it is most closely related to. Recent fossils revealed a group of extinct, four-limbed marine lizards called mosasauroids which could be closely related to the snakes' most primitive ancestor, the Pachyrhachis. Except for the missing forelimbs, the Pachyrhachis share the same feature like a separate astralagus and calcaneum which to most squamates are fused.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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Multituberculate phylogeny
Article Abstract:
Studies on the fossils of multituberculate mammals leave much to be desired, despite their provision of invaluable anatomical information. They have failed to include relevant fossil taxa such as the dryolestid Gobiconodon and the triconodont Gobiconodon. They also ally taxa with multituberculates and therians without explaining the rationale for the alliance. The situation calls for reevaluating multituberculate relationships on a larger sampling of taxa and character.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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