Notoungulates (Notoungulata)

Notoungulates –  literally “southern ungulates.” – may be the most emblematic of all extinct South American mammals. Notoungulates were the most abundant of the native South American ...

Bisons and other Bovines and Bovidaes

From left to right : Long-horned Bison(extinct), Pelorovis Antiquus(extinct), Ancient Bison(extinct), Steppe Bison(extinct), Aurochs(extinct), Holocene Bison(extinct), Cebu dwarf Buffalo(extinct), P...

Giraffids (Giraffidae)
The giraffids evolved from a group of even-toed ungulates in the early Miocene almost 25 million years ago. They formed part of a relatively late mammal diversification that also produced cattle, antelopes, and dee...

Cervidae

The Cervidae first appear as fossils in the early Miocene of Asia, where they expanded into a wide variety of niches (and were thus able to dominate over the bovids which arrived later). During the Miocene, members of this fami...

Cimolestids (Cimolesta)
The largest cimolestid is Coryphodon, 1 metre (3.3 ft) high at the shoulder and 2.25 metres (7.4 ft) long.

Camels, Llamas, Guanacos, Alpacas, and Vicuсas

1. Camelops 2. Oxydactylus 3. Aepycamelus 4. Alticamelus 5. Stenomylus

The largest fossil Odontocete ("toothed whale") was the Miocenephyseteroid whale Livyatan melvillei which was estimated to be between 13.5 and 17.5 meters in length. One notable feature of L. melvillei was its teeth which could exceed 36...

Whales

The evolution of whales has been a mystery. How did a large, big-brained mammal -- air-breathing, warm-blooded, giving birth to live young -- come to live entirely in water, when mammals evolved on land? The discovery of many fos...

Sirenians (Sirenia)

1. Metaxytherium 2. Protosiren 3. Hydrodamalis 4. Prorastomus  5. Pezosiren

Entelodonts

Entelodonts (properly Entelodontidae) have generally been regarded as suiforms (close kin to pigs and peccaries) but some recent analyses have found the sampled members of the group to be members of the hippo + cetacea...

Hippopotamuses, Choeropsis & Hexaprotodons
1. Kenyapotamus 2. Siamotherium 3. Archaeopotamus 4. Anthracotherium 5. Merycopotamus
Until 1909, naturalists grouped hippos with pigs, based on molar patterns. Several lines of evidence, f...

Rodents (Rodentia)

The single largest group of mammals is the Rodentia. Most non-flying mammals are rodents: there are about 1,500 living rodent species (out of about 4,000 living mammals overall). Most people are familiar with mice, ra...