Artiocetus

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Artiocetus
Temporal range:
Ma
↓
Skull of A. clavis on display at Oxford University Museum of Natural History
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: †Protocetidae
Subfamily: †
Protocetinae
Genus: †Artiocetus
Gingerich et al., 2001
Species:
†A. clavis
Binomial name
†Artiocetus clavis
Gingerich et al., 2001

Artiocetus is an

whales belonging to the family Protocetidae. It was a close relative to Rodhocetus and its tarsals indicate it resembled an artiodactyl.[1]

Etymology

Artiocetus' name arises from a combination of cetus and artiodactyl, as this fossil was the first to show that early whales possessed artiodactyl-like ankles.

Artiocetus belongs to the infraorder Cetacea, which includes

Gaia and Pontus
, and said to resemble a gigantic whale or fish.

Artiodactyla refers to the mammal order of

astragalus
is another key feature which has a double-pulley structure in artiodactyls, giving the foot greater flexibility.

Description

Artiocetus clavis was a small whale measuring 2–3 m (6.6–9.8 ft) long.

anthracotheres, ancestors of the hippopotamus, are thought to have descended from an ancestor shared with the whale.[3]

Like Rodhocetus, Artiocetus had limbs comparable to Ambulocetus but larger fore and hind feet, which were probably webbed. They could probably move on land, but rather clumsily like a modern seal.[4]

Protocetidae were the first group of whales to develop tail flukes, which suggests they were quick, agile predators. Though Protocetidae as a family possessed tail flukes, it has been suggested that Artiocetus did not. Thewissen et al. states that "Artiocetus had a long tail and thus probably lacked a tail fluke".[5]

Fossil finds

Fossils located in 2001 in the

artiodactyls),[3]
suggesting that early whales had fore and hind limbs. The distribution of fossils in Indo-Pakistan, Africa, Europe, and North America suggests that this species preferred a warmer sea climate, preferably in the tropics.

There is no commonly agreed ancestry of the whale, but they are thought to have evolved from an early group of carnivorous

even-toed ungulates
.

DNA studies have suggested that the hippopotamus is the closest land relative to the whale. Artiocetus fossils represent intermediate forms between land-living

ungulates
and whales, lending support to the theory that whales and hippopotami descended from a common ancestor.

The discovery of this fossil is important as it helped solidify the theory that whales shared a common ancestor with Artiodactyla. In 2005, an international team of scientists suggested that whales and hippopotami share a common water and terrestrial dwelling ancestor, which lived 50 to 60 million years ago. Two groups emerged from this common ancestor: early cetaceans, which in time returned to the sea permanently, and a large group of superficially pig-like land-based mammals called

anthracotheres. The only surviving descendants of anthracotheres are the common and pygmy hippopotamuses
.

References

  1. ISBN 978-0801884726
    .
  2. PMID 19194487
    .
  3. ^
    S2CID 21441797. Supplementary Material: Distinctive characteristics of artiodactyl ankle bones
  4. ISBN 978-0198507604
    .
  5. S2CID 26449214
    . Retrieved 21 December 2012.

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Artiocetus&oldid=1158384501"