MULTITUBERCULATA

This article appears in Volume V18, Page 966 of the Encyclopedia Britannica.

Encyclopedia Britannica - Main :: MOS-NAN

MULTITUBERCULATA , a group of

extinct

EXTINCT

mammals, mostly of small size, whose remains are met with in strata ranging from the Trias to the Eocene, both in Europe and in North America. They are mostly known by their lower jaws, and take their name from the fact that the grinding teeth (fig. 2, m. 1 and 2; and fig. 3 a. b. c.)

bear

two or three longitudinal rows 0f tubercles, or are provided with tubercles round the edges. From this feature these otherwise unknown animals are believed to be related to the existing egg-laying mammals (duck-billed platypus and spiny ant-eater), constituting the order Monotremata, and are therefore provisionally placed near that group. The largest representative of the Multituberculata is Polymastodon from the Lower Eocene of New

Mexico

; the same beds also yield the smaller Ptilodus; while from corresponding strata at Rheims, in France, has been obtained the nearly allied Neoplagiaulax. The latter takes its name from its resemblance to Plagiaulax (

figs

FIGS

. 1 and 2) from the Purbeck

bras

BRAS

.
m
strata of

Swanage

SWANAGE

, Dorsetshire, which was one of the first-known members of the group. These have cutting teeth in front and multituberculate molars behind. Allodon and Ctenacodon represent the group in the Cretaceous of North America; and the English Purbeck genus Bolodon, in which all the cheek-teeth are multituberculate, also belongs here. Stereognathus (fig. 3) is another English Upper Oolitic type. Single teeth from the Rhaetic of England and Wurttemberg described as Microlestes apparently indicate the earliest member of the group. A skull
from the Upper Triassic Karoo beds of

South

SOUTH
SOUTH, ROBERT (1634–1716)

Africa described as Tritylodon longaevus, which has multituberculate molar teeth, was also at first placed in this group, but has been subsequently regarded as a reptile, although Dr R. Broom considers that the
Fig. 2.-Lower Jaw of Plagiaulax FIG. 3.-Fragment of Jaw of

minor

, from

Swanage

SWANAGE

. p. 1-4 Stereognathus oolithicus in
premolars ; m. 1 and 2 molars. matrix. a b c, molars.

original

ORIGINAL

determination is correct. Possibly a fore-limb from the same formation described as Theriodesmus phylarchus indicates a similar or allied animal. Not improbably Tritylodon indicates a direct link between the multituberculate mammals and the anomodont reptiles of the Permian and Trias. (R. L.*)

End of Article: MULTITUBERCULATA

If you wish, you can link directly to this article.

<a href="http://jcsm.org/StudyCenter/Encyclopedia/MOS_NAN/MULTITUBERCULATA.html">
MULTITUBERCULATA
</a>

(Previous)
MULTIPLEPOINDING

(Next)
MUMMERS

JCSM was founded in 1997 and exists to help the community and bring people into a life-changing and productive relationship with Jesus Christ. JCSM offers over 200,000 free web pages, including its weekly inspirational emails that were sent continuously for over a decade.

Jesus Christ Saves Ministries
P.O. Box 9297
San Diego, CA 92169
1-888-887-0417 or Email