Mesonychia

Mesonychia
	Live reconstruction of Mesonyx
Temporal occurrence
	Paleocene to Eocene
Locations
	Asia; North America;
Systematics
	Amniotes (Amniota)
	Synapsids (Synapsida)
	Mammals (mammalia)
	Higher mammals (Eutheria)
	Laurasiatheria
	Mesonychia
Scientific name
	Mesonychia
	Van Valen , 1966

The mesonychia are an extinct order of mammals . They were the only real carnivores among the ungulates . The best known species were Mesonyx and Andrewsarchus . Previously they were placed in the order Acreodi as the family Mesonychidae. The mesonychia have long been believed to be the ancestors of the whales .

features

The mesonychia were somewhat reminiscent of dogs with large heads. Their molars were well suited for cutting meat, but instead of claws on their feet, as we know them from today's predators , they had hooves . The earliest species still had 5 toes on each foot and performed with the entire sole. Later ones like Pachyaena , a mesonychid from the latest Paleocene, only had 4 toes and stepped on with their toes.

Tribal history

The Mesonychia probably developed in the early Paleocene of Asia. One of the first forms is yangtanlestes . From the middle Paleocene they spread to other continents with Dissacus and Ankalagon . Dissacus was about the size of a coyote and spread over the entire northern hemisphere, the Ankalagon from North America was much larger, and its skull was the size of a bear. However, these animals had disproportionately large skulls compared to their body size.

In the Paleocene there were three families of the Mesonychia, the Triisodontidae, the Mesonychidae and the little-known Hapalodectidae. The former, together with the Arctocyonidae, were among the dominant predators of the first mammalian societies at the beginning of the Tertiary. Triisodontic species such as Eoconodon and its successor Triisodon were among the largest mammals of the lower and middle Paleocene, when all existing mammals were still quite small. The largest triisodont was Andrewsarchus from the middle Eocene of Asia, who is also the largest carnivorous land mammal in the history of the earth. Mesonyx and Pachyaena belonged to the Mesonychidae family.

Web links

Commons : Mesonychia - Collection of images, videos and audio files

Carnivores, creodonts and carnivorous ungulates: Mammals become predators

swell

^ Geisler, JH and Uhen, MD: Morphological support for a close relationship between hippos and whales . In: Journal of Vertebrate Paleontology . 23, No. 4, 2003, pp. 991-996. doi : 10.1671 / 32 .
↑ Geisler, JH and Uhen, MD: Phylogenetic relationships of extinct cetartiodactyls: results of simultaneous analyzes of molecular, morphological, and stratigraphic data . In: Journal of Mammalian Evolution . 12, No. 1 and 2, 2005, pp. 145-160. doi : 10.1007 / s10914-005-4963-8 .
↑ Boisserie, J.−R., Lihoreau, F., and Brunet, M .: The position of Hippopotamidae within Cetartiodactyla . In: Proceedings of the National Academy of Sciences . 102, No. 5, 2005, pp. 1537-1541. doi : 10.1073 / pnas.0409518102 . PMID 15677331 . PMC 547867 (free full text).

[Geisler-1] Geisler, JH and Uhen, MD: Morphological support for a close relationship between hippos and whales . In: Journal of Vertebrate Paleontology . 23, No. 4, 2003, pp. 991-996. doi : 10.1671 / 32 .

[Geisler2-2] Geisler, JH and Uhen, MD: Phylogenetic relationships of extinct cetartiodactyls: results of simultaneous analyzes of molecular, morphological, and stratigraphic data . In: Journal of Mammalian Evolution . 12, No. 1 and 2, 2005, pp. 145-160. doi : 10.1007 / s10914-005-4963-8 .

[Boisserie-3] Boisserie, J.−R., Lihoreau, F., and Brunet, M .: The position of Hippopotamidae within Cetartiodactyla . In: Proceedings of the National Academy of Sciences . 102, No. 5, 2005, pp. 1537-1541. doi : 10.1073 / pnas.0409518102 . PMID 15677331 . PMC 547867 (free full text).