Cetacea

Order CETACEA

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Learn more about Cetaceans from the

University of Michigan Animal Diversity Web or
University of California Museum of Paleontology
Texas Marine Mammal Stranding Network
Natural History Museum of Los Angeles County
Texas Cetaceans
The Order Cetartiodactyla is based on molecular evidence that hippopotamuses are more closely related to whales than they are to other artiodactyls. Early cetacean fossils from Pakistan demonstrate that whales are artiodactyls. More from National Geographic
- Thewissen, J. G. M., E.M. Williams, L.J. Roe, and S.T. Hussain. 2001. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls, Nature 413: 277-281. Philip D. Gingerich, et al. 2001. Origin of whales from early artiodactyls: Hands and feet of Eocene Protocetidae from Pakistan, Science, 293: 2239-2242.

Traits

exclusively aquatic
fusiform body with shortened neck and elongate tail [Fig. 16.2]
tail modified into horizontal flukes (supported only by connective tissue)
pelvic girdle reduced to vestigial
paddle shaped anterior limbs [Fig. 16.3]
highly modified, telescoped skull [Fig. 16.4]
external nares dorsally located [Fig. 16.5]
nares connects directly to lungs
diving adaptations Gerald L. Kooyman and Paul J Ponganis
adaptations in diving mammals from Clarenville High

Suborder Mysticeti--baleen whales [Table 16.1]

Baleen [Figs. 16.8, 16.9]
learn more about Baleen Whales from SeaWorld
- feeding in baleen whales

Balaenidae (2, 3) Bowhead and right whales
1. skimmers [fig 16.16]

Balaenopteridae (2, 6) Rorquals: the fin backed and humback whales

gulpers [fig 16.10]
1. Balaenoptera acutorostrata [minke] ;8-10 m, up to 9000 kg. Minke whales are the most numerous of the baleen whales.
2. Balaenoptera musculus [blue whale]: up to 30 m, 200,000 kg

Megaptera novaeangliae [humpback whale] [Fig. 13-15, 13-16]

Listen to the songs of the humpback whale.

humpbackwhale feeding call

Photograph by Gerald and Buff Corsi © California Academy of Sciences

Eschrichtiidae (1, 1) Gray whale

bottom scooper
thermoregulation in the tongues of grey whales

Eschrichtius robustus,
Gray Whale. Photograph by Gerald and Buff Corsi © California Academy of Sciences

Neobalaenidae (1, 1) Pigmy right whale

Suborder Odontoceti [Table 16.1]

Toothed whales
Echolocation [Fig. 16.11]

Delphinidae (17, 32)

Dolphins, pilot whales, spotted dolphins, spinner dolphins (tuna fish industry), orca whales [Fig. 13-17]
Tursiops truncatus, Atlantic bottle-nosed dolphin, is the common dolphin of the Texas coast. They can grow to be 10 feet (3.0 m) long and weigh as much as 600 pounds (275 kg)
What is the difference between dolphins and porpoises from the LACM
learn more about Bottled-nosed dolphins and other toothed-whales from SeaWorld.

Dolphins, Photograph by Susan Middleton © California Academy of Sciences.

Globicephala sp.
Pilot Whale, Blackfish. Photograph by John H. Tashjian © California Academy of Sciences.

Monodontidae (2, 2) Narwhal, beluga
Phocoenidae (4, 6) Porpoises
Physeteridae (2, 3) Sperm whales Physeter: 18 m long, 53,000 kg.
Platanistidae (4, 5) River dolphins

Ziphiidae (6, 19) Beaked whales

A rare, complete Hubbs' Beaked Whale (Mesoplodon carlhubbsi) skeleton is on display at Humboldt State University. According to the website article, "[b]eaked whales are among the least known of all living whales. This toothed whale lives offshore above deep ocean canyons in the Pacific Ocean between North America and Japan."
Thanks to Drs. Brian Arbogast and Steven Smith (pictured, third from left) of Humbolt State University for supplying this photograph.

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