Evolution of dental wear and diet during the origin of whales

Thewissen, J. G. M.; Sensor, Jennifer D.; Clementz, Mark T.; Bajpai, Sunil

doi:10.1666/10038.1

Cited by 50 publications

(40 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This phylum was detected at high abundance in many ruminants, such as Sika deer (Cervus nippon), goat (Capra hircus), and reindeer (Rangifer tarandus platyrhynchus), because the bacteria are able to ferment mucins and plant polysaccharides [6,25,38,44]. It was reported that the ancestors of cetaceans derived from artiodactyls and early cetartiodactyls (Artiodactyla plus Cetacea), which were once thought to be herbivorous and omnivorous [50]. Thereafter, the diet of cetaceans could have shifted from plants to high-protein fish.…”

Section: Discussionmentioning

confidence: 99%

Fecal Bacterial Composition of the Endangered Yangtze Finless Porpoises Living Under Captive and Semi-natural Conditions

et al. 2015

View full text Add to dashboard Cite

Intestinal microbiota is essential to the health and physiology of host animals. We undertook the first microbiological study of the fecal bacterial composition from critically endangered (CR) Yangtze finless porpoises (Neophocaena asiaeorientalis asiaeorientalis; YFPs) living under captive and semi-natural conditions using both high-throughput sequencing method and 16S rRNA gene clone library method. As determined by high-throughput sequencing of V3-V4 regions of the 16S rRNA gene, seminatural samples harbored 30 and 36 operational taxonomic units (OTUs), which was more than the 22 and 27 OTUs detected from YFPs living in captivity. In captive YFPs Firmicutes was the predominant phylum, whereas this was Proteobacteria for YFPs living in semi-nature conditions. This suggests habitat-specific fecal bacterial composition of YFPs. Plesiomonas spp. and Aeromonas spp., which are potentially pathogenic, were identified in all the feces. Bacterial diversity from one porpoise living in captivity was also determined by constructing a 16S rRNA gene clone library and only 1 phylum was identified. Highthroughput sequencing was more effective at determining the bacterial diversity compared to the 16S rRNA gene clone library. This study provides important information for the management and conservation of the CR YFPs.

show abstract

Section: Discussionmentioning

confidence: 99%

Fecal Bacterial Composition of the Endangered Yangtze Finless Porpoises Living Under Captive and Semi-natural Conditions

et al. 2015

View full text Add to dashboard Cite

show abstract

“…We focused on fossils from the Eocene, when cetaceans strongly reduced precise occlusion (Thewissen et al, 2011) and the Oligocene, when polydonty and homodonty originated in both odontocetes (Fordyce, 2003) and mysticetes (Deméré et al, 2008). In mysticetes, these changes preceded the loss of teeth altogether (Deméré et al, 2008).…”

Section: Methodsmentioning

confidence: 99%

Development and evolution of the unique cetacean dentition

Armfield

Zheng

Bajpai

et al. 2013

PeerJ

Self Cite

View full text Add to dashboard Cite

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.

show abstract

“…Knowledge of the movements and feeding habits of extant cetaceans has significantly benefited from the application of stable isotope analysis , a tool that has also been applied to address questions of the ecology of early fossil whales (Thewissen et al, 1996;Roe et al, 1998;Clementz et al, 2006;Thewissen et al, 2011). Differences in the stable isotopic composition of cetacean prey items, or waters directly or incidentally ingested when feeding, are subsequently incorporated into cetacean tissues and biological apatites or "bioapatites" (e.g., bone, dentin, enamel; typically, apatite with carbonate and hydroxyl components), leaving an isotopic label that can be traced back to the original food or water source (Yoshida and Miyazaki, 1991;Clementz and Koch, 2001).…”

Section: Introductionmentioning

confidence: 99%