Protoclepsydrops Explained

Protoclepsydrops is an extinct genus of early synapsids, found in Joggins, Nova Scotia.^[1] The name means 'first Clepsydrops, and refers to it being the predecessor of the other early synapsid Clepsydrops.

Description

Like Archaeothyris, Protoclepsydrops resembled a modern lizard in superficial appearance. However, Protoclepsydrops had primitive vertebrae with tiny neural processes typical of their amniote ancestors. Protoclepsydrops is known from a few vertebrae and some humeri.^[2]

Classification

Its skeletal remains indicate that it may have been more closely related to synapsids than to sauropsids, making it a possible stem-mammal. If so, it is the oldest synapsid known, though its status is unconfirmed because its remains are too fragmentary. Protoclepsydrops lived slightly earlier than Archaeothyris.^[3] It is possibly synonymous with Asaphestera, another early synapsid discovered from the same locality.^[4]

See also

• List of pelycosaurs
• Evolution of mammals
• List of transitional fossils
• Carboniferous tetrapods
• Clepsydrops

External links

• Ophiacodontids

Notes and References

1. Carroll. Robert L.. The earliest reptiles. Journal of the Linnean Society of London, Zoology. 1964. 45. 304. 61–83. 10.1111/j.1096-3642.1964.tb00488.x.
2. Reisz, R., 1972. Pelycosaurian reptiles from the middle Pennsylvanian of North America. Harvard University.
3. Benton M.J. and Donoghue P.C.J. 2006. Palaeontological evidence to date the tree of life. Molecular biology and evolution. 24(1): 26 - 53. https://web.archive.org/web/20121103190705/http://mbe.oxfordjournals.org/content/24/1/26.full.pdf+html
4. Mann . Arjan . Gee . Bryan M. . Pardo . Jason D. . Marjanović . David . Adams . Gabrielle R. . Calthorpe . Ami S. . Maddin . Hillary C. . Anderson . Jason S. . Sansom . Robert . Reassessment of historic ‘microsaurs’ from Joggins, Nova Scotia, reveals hidden diversity in the earliest amniote ecosystem . Papers in Palaeontology . Wiley . 5 May 2020 . 2056-2802 . 10.1002/spp2.1316 .