First record of the Miocene hominoid Sivapithecus from Kutch, Gujarat state, western India.
Animals; India; Biological Evolution; Geology; *Archaeology; *Hominidae/anatomy & histology
Hominoid remains from Miocene deposits in India and Pakistan have played a pivotal role in understanding the evolution of great apes and humans since they were first described in the 19th Century. We describe here a hominoid maxillary fragment preserving the canine and cheek teeth collected in 2011 from the Kutch (= Kachchh) basin in the Kutch district, Gujarat state, western India. A basal Late Miocene age is proposed based on the associated faunal assemblage that includes Hipparion and other age-diagnostic mammalian taxa. Miocene Hominoidea are known previously from several areas of the Siwalik Group in the outer western Himalayas of India, Pakistan, and Nepal. This is the first record of a hominoid from the Neogene of the Kutch Basin and represents a significant southern range extension of Miocene hominoids in the Indian peninsula. The specimen is assigned to the Genus Sivapithecus, species unspecified.
Bhandari Ansuya; Kay Richard F; Williams Blythe A; Tiwari Brahma Nand; Bajpai Sunil; Hieronymus Tobin L
PloS one
2018
2018
<a href="http://doi.org/10.1371/journal.pone.0206314" target="_blank" rel="noreferrer noopener">10.1371/journal.pone.0206314</a>
Thewissen et al. reply.
LETTERS to the editor; WHALES
Replying to: J. H. Geisler & J. M. Theodor 458, 10.1038/nature07776 (2009)The analysis of Geisler and Theodor confirms our main phylogenetic result, that raoellids are, or include, the sister group to cetaceans. Their study expands on our findings by inferring that hippopotamids are the sister group to the combined raoellid–cetacean clade, whereas our paper had explicitly stated that our data could not address the position of the extant artiodactyl families. [ABSTRACT FROM AUTHOR]
Thewissen J G M; Cooper Lisa Noelle; Clementz Mark T; Bajpai Sunil; Tiwari B N
Nature
2009
2009-03-19
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/nature07775" target="_blank" rel="noreferrer noopener">10.1038/nature07775</a>
Development and evolution of the unique cetacean dentition.
Teeth; Cetacea; Cetacean; Evo-devo; Paleontology
The evolutionary success of mammals is rooted in their high metabolic rate. A high metabolic rate is sustainable thanks to efficient food processing and that in turn is facilitated by precise occlusion of the teeth and the acquisition of rhythmic mastication. These major evolutionary innovations characterize most members of the Class Mammalia. Cetaceans are one of the few groups of mammals in which precise occlusion has been secondarily lost. Most toothed whales have an increased number of simple crowned teeth that are similar along the tooth row. Evolution toward these specializations began immediately after the time cetaceans transitioned from terrestrial-to-marine environments. The fossil record documents the critical aspects of occlusal evolution of cetaceans, and allows us to pinpoint the evolutionary timing of the macroevolutionary events leading to their unusual dental morphology among mammals. The developmental controls of tooth differentiation and tooth number have been studied in a few mammalian clades, but nothing is known about how these controls differ between cetaceans and mammals that retain functional occlusion. Here we show that pigs, a cetacean relative with regionalized tooth morphology and complex tooth crowns, retain the typical mammalian gene expression patterns that control early tooth differentiation, expressing Bmp4 in the rostral (mesial, anterior) domain of the jaw, and Fgf8 caudally (distal, posterior). By contrast, dolphins have lost these regional differences in dental morphology and the Bmp4 domain is extended into the caudal region of the developing jaw. We hypothesize that the functional constraints underlying mammalian occlusion have been released in cetaceans, facilitating changes in the genetic control of early dental development. Such major developmental changes drive morphological evolution and are correlated with major shifts in diet and food processing during cetacean evolution.
Armfield Brooke A; Zheng Zhengui; Bajpai Sunil; Vinyard Christopher J; Thewissen J G M
PeerJ
2013
1905-07
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/10.7717/peerj.24" target="_blank" rel="noreferrer noopener">10.7717/peerj.24</a>
First record of the Miocene hominoid Sivapithecus from Kutch, Gujarat state, western India.
Hominoid remains from Miocene deposits in India and Pakistan have played a pivotal role in understanding the evolution of great apes and humans since they were first described in the 19th Century. We describe here a hominoid maxillary fragment preserving the canine and cheek teeth collected in 2011 from the Kutch (= Kachchh) basin in the Kutch district, Gujarat state, western India. A basal Late Miocene age is proposed based on the associated faunal assemblage that includes Hipparion and other age-diagnostic mammalian taxa. Miocene Hominoidea are known previously from several areas of the Siwalik Group in the outer western Himalayas of India, Pakistan, and Nepal. This is the first record of a hominoid from the Neogene of the Kutch Basin and represents a significant southern range extension of Miocene hominoids in the Indian peninsula. The specimen is assigned to the Genus Sivapithecus, species unspecified.
Bhandari Ansuya; Kay Richard F; Williams Blythe A; Tiwari Brahma Nand; Bajpai Sunil; Hieronymus Tobin
PloS one
2018
1905-7
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/10.1371/journal.pone.0206314" target="_blank" rel="noreferrer noopener">10.1371/journal.pone.0206314</a>
Anthracobunids from the middle eocene of India and pakistan are stem perissodactyls.
Animals; *Fossils; India; Dugong; Elephants; Pakistan
Anthracobunidae is an Eocene family of large mammals from south Asia that is commonly considered to be part of the radiation that gave rise to elephants (proboscideans) and sea cows (sirenians). We describe a new collection of anthracobunid fossils from Middle Eocene rocks of Indo-Pakistan that more than doubles the number of known anthracobunid fossils and challenges their putative relationships, instead implying that they are stem perissodactyls. Cranial, dental, and postcranial elements allow a revision of species and the recognition of a new anthracobunid genus. Analyses of stable isotopes and long bone geometry together suggest that most anthracobunids fed on land, but spent a considerable amount of time near water. This new evidence expands our understanding of stem perissodactyl diversity and sheds new light on perissodactyl origins.
Cooper Lisa Noelle; Seiffert Erik R; Clementz Mark; Madar Sandra I; Bajpai Sunil; Hussain S Taseer; Thewissen J G M
PloS one
2014
1905-7
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/10.1371/journal.pone.0109232" target="_blank" rel="noreferrer noopener">10.1371/journal.pone.0109232</a>
Aquatic Habits of Cetacean Ancestors: Integrating Bone Microanatomy and Stable Isotopes.
*Ecosystem; Animals; Bone and Bones/anatomy & histology/metabolism; Cetacea/*physiology; Isotope Labeling; Isotopes/metabolism
The earliest cetaceans were interpreted as semi-aquatic based on the presence of thickened bones and stable oxygen isotopes in tooth enamel. However, the origin of aquatic behaviors in cetacean relatives (e.g., raoellids, anthracotheres) remains unclear. This study reconstructs the origins of aquatic behaviors based on long bone microanatomy and stable oxygen isotopes of tooth enamel in modern and extinct cetartiodactylans. Our findings are congruent with published accounts that microanatomy can be a reliable indicator of aquatic behaviors in taxa that are obligatorily aquatic, and also highlight that some "semi-aquatic" behaviors (fleeing into the water to escape predation) may have a stronger relationship to bone microanatomy than others (herbivory in near-shore aquatic settings). Bone microanatomy is best considered with other lines of information in the land-to-sea transition of cetaceans, such as stable isotopes. This study extends our understanding of the progression of skeletal phenotypes associated with habitat shifts in the relatives of cetaceans.
Cooper Lisa Noelle; Clementz Mark T; Usip Sharon; Bajpai Sunil; Hussain S Taseer; Hieronymus Tobin L
Integrative and comparative biology
2016
2016-12
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<a href="http://doi.org/10.1093/icb/icw119" target="_blank" rel="noreferrer noopener">10.1093/icb/icw119</a>
Whales originated from aquatic artiodactyls in the Eocene epoch of India.
*Phylogeny; *Whales/anatomy & histology/classification/physiology; Animals; ARTIODACTYLA; BICUSPIDS; CETACEA; EOCENE stratigraphic geology; India; INDIA; MAMMALOGICAL research; Pakistan; Time Factors; UNGULATES; WHALES
Although the first ten million years of whale evolution are documented by a remarkable series of fossil skeletons, the link to the ancestor of cetaceans has been missing. It was known that whales are related to even-toed ungulates (artiodactyls), but until now no artiodactyls were morphologically close to early whales. Here we show that the Eocene south Asian raoellid artiodactyls are the sister group to whales. The raoellid Indohyus is similar to whales, and unlike other artiodactyls, in the structure of its ears and premolars, in the density of its limb bones and in the stable-oxygen-isotope composition of its teeth. We also show that a major dietary change occurred during the transition from artiodactyls to whales and that raoellids were aquatic waders. This indicates that aquatic life in this lineage occurred before the origin of the order Cetacea.
Thewissen J G M; Cooper Lisa Noelle; Clementz Mark T; Bajpai Sunil; Tiwari B N
Nature
2007
2007-12
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<a href="http://doi.org/10.1038/nature06343" target="_blank" rel="noreferrer noopener">10.1038/nature06343</a>
Eocene evolution of whale hearing.
*Biological Evolution; *Fossils; Air; Animals; Ear/*anatomy & histology/*physiology; EVOLUTION (Biology); FOSSILS; HEARING; Hearing/*physiology; MAMMALS; Mammals/anatomy & histology/physiology; Phylogeny; SOUND; Water; WHALES; Whales/*anatomy & histology/*physiology
The origin of whales (order Cetacea) is one of the best-documented examples of macroevolutionary change in vertebrates. As the earliest whales became obligately marine, all of their organ systems adapted to the new environment. The fossil record indicates that this evolutionary transition took less than 15 million years, and that different organ systems followed different evolutionary trajectories. Here we document the evolutionary changes that took place in the sound transmission mechanism of the outer and middle ear in early whales. Sound transmission mechanisms change early on in whale evolution and pass through a stage (in pakicetids) in which hearing in both air and water is unsophisticated. This intermediate stage is soon abandoned and is replaced (in remingtonocetids and protocetids) by a sound transmission mechanism similar to that in modern toothed whales. The mechanism of these fossil whales lacks sophistication, and still retains some of the key elements that land mammals use to hear airborne sound.
Nummela Sirpa; Thewissen J G M; Bajpai Sunil; Hussain S Taseer; Kumar Kishor
Nature
2004
2004-08
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/nature02720" target="_blank" rel="noreferrer noopener">10.1038/nature02720</a>
Sound transmission in archaic and modern whales: anatomical adaptations for underwater hearing.
*Adaptation; *Ear/anatomy & histology/physiology; *Whales/anatomy & histology/physiology; Animals; Biological Evolution; Fossils; Hearing/*physiology; Phonetics; Physiological; Sound; Water
The whale ear, initially designed for hearing in air, became adapted for hearing underwater in less than ten million years of evolution. This study describes the evolution of underwater hearing in cetaceans, focusing on changes in sound transmission mechanisms. Measurements were made on 60 fossils of whole or partial skulls, isolated tympanics, middle ear ossicles, and mandibles from all six archaeocete families. Fossil data were compared with data on two families of modern mysticete whales and nine families of modern odontocete cetaceans, as well as five families of noncetacean mammals. Results show that the outer ear pinna and external auditory meatus were functionally replaced by the mandible and the mandibular fat pad, which posteriorly contacts the tympanic plate, the lateral wall of the bulla. Changes in the ear include thickening of the tympanic bulla medially, isolation of the tympanoperiotic complex by means of air sinuses, functional replacement of the tympanic membrane by a bony plate, and changes in ossicle shapes and orientation. Pakicetids, the earliest archaeocetes, had a land mammal ear for hearing in air, and used bone conduction underwater, aided by the heavy tympanic bulla. Remingtonocetids and protocetids were the first to display a genuine underwater ear where sound reached the inner ear through the mandibular fat pad, the tympanic plate, and the middle ear ossicles. Basilosaurids and dorudontids showed further aquatic adaptations of the ossicular chain and the acoustic isolation of the ear complex from the skull. The land mammal ear and the generalized modern whale ear are evolutionarily stable configurations, two ends of a process where the cetacean mandible might have been a keystone character.
Nummela Sirpa; Thewissen J G M; Bajpai Sunil; Hussain Taseer; Kumar Kishor
Anatomical record (Hoboken, N.J. : 2007)
2007
2007-06
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/10.1002/ar.20528" target="_blank" rel="noreferrer noopener">10.1002/ar.20528</a>