Protictis Explained

Protictis ("first weasel") is an extinct paraphyletic genus of placental mammals from extinct subfamily Didymictinae within extinct family Viverravidae, that lived in North America from early Paleocene to middle Eocene.^{[1] [2]}

Etymology

The name of genus Protictis comes and Latin ictis.

Description

Protictis was a mongoose-like animal that was lightly built.^[3] The species had variable sizes. Parts of the skeleton of P. haydenianus are known and this species was about 75 cm long, comparable to the related Didymictis and the modern day Asian civets.^[4] The skull of P. simpsoni shows that this species was larger than P. haydenianus. P. minor on the other hand was smaller than P. haydenianus. The morphology of the limb bones of P haydenianus points at a scansorial lifestyle. Protictis had two times as many teeth as modern carnivores. The characteristic carnassials of carnivores were already clearly developed in Protictis, but the long and pointy teeth show that insects were still a major component of this diet. Endocasts of the skull shows that both vision and hearing were important senses, but the position of the eye sockets shows that threedimensional vision was not as well developed as in modern carnivores.^[5]

Classification and phylogeny

History of classification

Fossils of Protictis are found in the United States and Canada and date mainly from the early to late Paleocene. The holotype of first discovered species (a part of the upper and lowe jaw) were described in 1882 by Edward Drinker Cope based on finds in the San Juan Basin in New Mexico and classified as Didymictis haydenianus. William Diller Matthew described Protictis as a subgenus of Didymictis in 1937 and in 1966 MacIntyre classified it as a separate genus.

Taxonomy

Genus: †Protictis ^{(paraphyletic genus)}

Subgenus:	Species:	Distribution of the species and type locality:	Age:
	†P. agastor ^[6]	(Cedar Point Quarry in Wyoming)	60.9 - 56.2 Ma
	†P. haydenianus ^[7]	Montana San Juan Basin in New Mexico^[8] ^[9] Utah Wyoming	63.8 - 56.2 Ma
	†P. minor ^[10]	(New Mexico)	63.8 - 60.9 Ma
	†P. paralus ^[11]	(Alberta and Saskatchewan) Wyoming Judson in North Dakota	60.9 - 56.2 Ma
	†P. simpsoni	(New Mexico)	63.8 - 60.9 Ma
†Protictoides	†P. aprophatos ^[12]	(Wyoming)	46.2 - 39.7 Ma

Notes and References

1. Book: McKenna . Malcolm C. . Bell . Susan K. . Classification of Mammals Above the Species Level . 16 March 2015 . 1997 . Columbia University Press . New York . 978-0-231-11012-9.
2. J. J. Flynn (1998.) "Early Cenozoic Carnivora ("Miacoidea")." In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.) "Evolution of Tertiary Mammals of North America. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals." Cambridge University Press, Cambridge.
3. L. B. Halstead (1978.) "The Evolution of the Mammals." P. Lowe, Cornell University, 116 p.
4. R. E. Heinrich & P. Houde (2006) "Postcranial anatomy of Viverravus (Mammalia, Carnivora) and implications for substrate use in basal Carnivora." Journal of Vertebrate Paleontology, 26:2, 422-435
5. http://www.paleocene-mammals.de/predators.htm Carnivores, creodonts and carnivorous ungulates: Mammals become predators
6. P. D. Gingerich and D. A. Winkler. (1985.) "Systematics of Paleocene Viverravidae (Mammalia, Carnivora) in the Bighorn Basin and Clark's Fork Basin, Wyoming." Contributions from the Museum of Paleontology, University of Michigan 27(4):87-128
7. E. D. Cope (1882) "Synopsis of the Vertebrata of the Puerco Eocene epoch - Supplement on a new Meniscotherium from the Wasatch epoch." Proceedings of the American Philosophical Society 20:461-471
8. T. E. Williamson and S. G. Lucas (1993) "Paleocene vertebrate paleontology of the San Juan Basin, New Mexico." New Mexico Museum of Natural History Bulletin 2:105-136
9. T. E. Williamson (1996) "The beginning of the age of mammals in the San Juan Basin, New Mexico; biostratigraphy and evolution of Paleocene mammals of the Nacimiento Formation." New Mexico Museum of Natural History and Science Bulletin 8:1-141
10. T. J. Meehan and R. W. Wilson (2002) "New viverravids from the Torrejonian (Middle Paleocene) of Kutz Canyon, New Mexico and the oldest skull of the order Carnivora." Journal of Paleontology 76(6):1091-1101
11. R. C. Holtzman (1978) "Late Paleocene Mammals of the Tongue River Formation, Western North Dakota." North Dakota Geological Survey Report of Investigations 65:1-88
12. J. J. Flynn and H. Galiano. (1982.) "Phylogeny of Early Tertiary Carnivora, With a Description of a New Species of Protictis From the Middle Eocene of Northwestern Wyoming" American Museum Novitates 2725:1-64