Search results
Results from the WOW.Com Content Network
The cetacean skeleton is largely made up of cortical bone, which stabilizes the animal in the water. For this reason, the usual terrestrial compact bones, which are finely woven cancellous bone , are replaced with lighter and more elastic material.
Ambulocetus (Latin ambulare "to walk" + cetus "whale") is a genus of early amphibious cetacean from the Kuldana Formation in Pakistan, roughly 48 or 47 million years ago during the Early Eocene . It contains one species, Ambulocetus natans (Latin natans "swimming"), known solely from a near-complete skeleton.
Species of the infraorder Cetacea A phylogenetic tree showing the relationships among cetacean families. [1]The evolution of cetaceans is thought to have begun in the Indian subcontinent from even-toed ungulates (Artiodactyla) 50 million years ago (mya) and to have proceeded over a period of at least 15 million years. [2]
Further excavation recovered most of the holotype's skeleton—most notably the hip, sacrum, and most of ribcage and thoracolumbar series (the spine excluding the neck, sacrum, and tail). These left the holotype about 80% complete by 2002, making it the most completely known cetacean from the time period. [5]
The latter is possible because while most cetacean "smiles" are fixed, the extra movement afforded by the beluga's unfused cervical vertebrae allows a greater range of apparent expression. [ 143 ] Between 1960 and 1992, the Navy carried out a program that included the study of marine mammals' abilities with sonar , with the objective of ...
Zygorhiza, mounted skeleton. Basilosaurids ranged in size from 4 to 16 m (13 to 52 ft) and were fairly similar to modern cetaceans in overall body form and function. [ 7 ] Some genera tend to show signs of convergent evolution with mosasaurs by having long serpentine body shape, which suggests that this body plan seems to have been rather ...
This category contains articles about Cetacea, including whales, dolphins and porpoises. ... Cetacean anatomy (8 P) Archaeoceti (5 C, 7 P) B. Baleen whales (5 C, 46 P) C.
Cetaceans also all categorically exhibit a large mandibular foramen within the lower jaw, which holds a fat pack and extends towards the ear, both of which are also associated with underwater hearing. "Pakicetus is the only cetacean in which the mandibular foramen is small, as is the case in all terrestrial animals. It thus lacked the fat pad ...