Eocene mammal faunas from northern Indo-Pakistan
america; enamel structure; gen; himalaya; marsupialia; northwest pakistan; nov-sp; oligocene; paleobiogeography; paleocene; Paleontology
We present a summary of the Eocene mammal faunas of Indo-Pakistan based on study of the known faunas and new collections. New taxa described here are the carpolestid Parvocristes oligocollis, the plesiadapid Jattadectes mamikheli (both new families for the subcontinent), the hyaenodontid Paratritemnodon jandewalensis, the arctocyonid Karakia longidens, the raoellid Khirtharia aurea, and the helaletid Jhagirilophus chorgalensis. Based on the faunal evidence and considering the geological setting, we also evaluate the uniformity of the Eocene faunas from northern Indo-Pakistan. Tentatively, we propose that three chronologically distinct faunas occur in Northern Indo-Pakistan. These are, from oldest to youngest, (1) the Banda Daud Shah Fauna, (2) the Ganda Kas Fauna, and (3) the Kalakot Fauna. Although there are broad similarities between these faunas and Eocene faunas of the Northern Hemisphere, the Indian subcontinent retained a highly distinctive fauna in that period.
Thewissen J G M; Williams E M; Hussain S T
Journal of Vertebrate Paleontology
2001
2001-07
Journal Article
<a href="http://doi.org/10.1671/0272-4634(2001)021%5B0347:emffni%5D2.0.co;2" target="_blank" rel="noreferrer noopener">10.1671/0272-4634(2001)021%5B0347:emffni%5D2.0.co;2</a>
The early radiations of cetacea (Mammalia): Evolutionary pattern and developmental correlations
archaeocete; artiodactyls; development; Environmental Sciences & Ecology; evolution; Evolutionary Biology; feet; fossil record; India; locomotor evolution; marine mammal; middle eocene; origin; pakistan; Stenella attenuata; time; whales
The origin and early evolution of Cetacea (whales, dolphins, and porpoises) is one of the best examples of macroevolution as documented by fossils. Early whales are divided into six families that differ greatly in their habitats, which varied from land to freshwater, coastal waters, and fully marine. Early cetaceans lived in the Eocene (55-37 million years ago), and they show an enormous morphological diversity. Toward the end of the Eocene the modem cetacean body plan originated, and this body plan remained more or less the same in the subsequent evolution. It is possible that some aspects of this body plan are rooted in constraints that are dictated by cetacean embryologic development and controlled by genes that affect many organ systems at once. It may be possible to use a study of patterns of correlations among morphological traits to test hypotheses of developmental links among organ systems.
Thewissen J G M; Williams E M
Annual Review of Ecology and Systematics
2002
2002
Journal Article
<a href="http://doi.org/10.1146/annurev.ecolysis.33.020602.095426" target="_blank" rel="noreferrer noopener">10.1146/annurev.ecolysis.33.020602.095426</a>
Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls.
*Biological Evolution; *Fossils; Animals; Bone and Bones/*anatomy & histology; Cetacea/anatomy & histology/*classification; Phylogeny; Skeleton; Whales/anatomy & histology/*classification
Modern members of the mammalian order Cetacea (whales, dolphins and porpoises) are obligate aquatic swimmers that are highly distinctive in morphology, lacking hair and hind limbs, and having flippers, flukes, and a streamlined body. Eocene fossils document much of cetaceans' land-to-water transition, but, until now, the most primitive representative for which a skeleton was known was clearly amphibious and lived in coastal environments. Here we report on the skeletons of two early Eocene pakicetid cetaceans, the fox-sized Ichthyolestes pinfoldi, and the wolf-sized Pakicetus attocki. Their skeletons also elucidate the relationships of cetaceans to other mammals. Morphological cladistic analyses have shown cetaceans to be most closely related to one or more mesonychians, a group of extinct, archaic ungulates, but molecular analyses have indicated that they are the sister group to hippopotamids. Our cladistic analysis indicates that cetaceans are more closely related to artiodactyls than to any mesonychian. Cetaceans are not the sister group to (any) mesonychians, nor to hippopotamids. Our analysis stops short of identifying any particular artiodactyl family as the cetacean sister group and supports monophyly of artiodactyls.
Thewissen J G; Williams E M; Roe L J; Hussain S T
Nature
2001
2001-09
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1038/35095005" target="_blank" rel="noreferrer noopener">10.1038/35095005</a>