Information om | Engelska ordet ARCHAEOCETES

Exempel på hur man kan använda ARCHAEOCETES i en mening

• The two modern parvorders of cetaceans – Mysticeti (baleen whales) and Odontoceti (toothed whales) – are thought to have separated from each other around 28–33 mya in a second cetacean radiation, the first occurring with the archaeocetes.
• Because of a shortage of forelimb fossils from other archaeocetes, it is not known if this arrangement is unique to basilosaurids, as some of the characteristics are also seen in Georgiacetus.
• The top-most breastbone, the manubrium, is T-shaped and wider than is long like archaeocetes, but plate-like and compressed like modern baleen whales.
• It existed in the early Lutetian age (47 million years ago) and is one of the oldest known protocetid archaeocetes.
• The lumbar vertebrae are large but relatively short (anteroposteriorly) compared to those of other archaeocetes; the diameter is almost the same as for Basilosaurus isis but the length is less than half of the latter.
• Uhen initially argued that the innominate would have been sufficiently large to support a weight-bearing hind limb—suggesting the animal was a protocetid, a group of more primitive archaeocetes—but also has anatomical features in common with basilosaurids—more derived and fully aquatic archaeocetes.
• Unlike modern baleen whales, Eomysticetus had a blowhole that was positioned ahead of the eyes, and the characteristics of its vertebrae and flipper bones are akin to those of archaeocetes like Basilosaurus.

Förberedelsen av sidan tog: 196,94 ms.