Fossil sirenia of the west Atlantic and Caribbean region. V. The most primitive known sirenian,<i>Prorastomus sirenoides</i>Owen, 1855

Savage, Robert J.; Domning, Daryl P.; Thewissen, J. G. M.

doi:10.1080/02724634.1994.10011569

Cited by 74 publications

(73 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The earliest members of each of these clades of marine mammals show adaptations of the feeding apparatus for feeding in water. For example, the earliest cetaceans have elongate rostra with their incisors along the rostral body, the earliest pinnipeds have a simplified dentition compared with other arctoids (Mitchell and Tedford, 1973), and the earliest sirenians have a narrow forceps-like snout for selective browsing of aquatic or nearshore vegetation (Savage et al, 1994). All of the isotopic studies performed to date are also consistent with this interpretation of the morphology.…”

Section: Discussionmentioning

confidence: 66%

“…2B; Domning and Gingerich, 1994;Domning, 2001a), but are found exclusively in marine rocks. Savage et al (1994) suggest that the prorastomids were fluviatile or estuarine, to marginal marine animals with diets similar to the modern sea cow, Trichechus. This conclusion is in part based on the lack of a great deal of deflection of the rostrum and the narrowness of the snout, which suggests a more selective browser than the seagrass grazers such as the modern Dugong (Savage et al, 1994;Domning, 2001c).…”

Section: Sirenian Evolutionary Historymentioning

confidence: 99%

See 1 more Smart Citation

Evolution of marine mammals: Back to the sea after 300 million years

Uhen

2007

The Anatomical Record

163

113

View full text Add to dashboard Cite

The fossil record demonstrates that mammals re-entered the marine realm on at least seven separate occasions. Five of these clades are still extant, whereas two are extinct. This review presents a brief introduction to the phylogeny of each group of marine mammals, based on the latest studies using both morphological and molecular data. Evolutionary highlights are presented, focusing on changes affecting the sensory systems, locomotion, breathing, feeding, and reproduction in Cetacea, Sirenia, Desmostylia, and Pinnipedia. Aquatic adaptations are specifically cited, supported by data from morphological and geochemical studies. For example, analysis of oxygen isotopes incorporated into fossil tooth enamel indicates whether these mammals foraged in (and, therefore, ingested) fresh water or sea water. Comparisons between groups are made to see if there are any common patterns, particularly relating to adaptations to aquatic life. Results show that aquatic characteristics evolved in mosaic patterns and that different morphological solutions to aquatic conditions were achieved separately in each of these groups. Changes in the axial and appendicular skeleton assist with locomotion for aquatic foraging. Nostril and eye placement modifications accommodate wading versus underwater foraging needs. All groups exhibit aquatic adaptations directly related to feeding, particularly changes in the dentition and rostrum. The earliest representatives of these clades all show morphological features that indicate they were feeding while in the water, suggesting that feeding ecology is a key factor in the evolution of marine mammals.Anat Rec 290:514-522, 2007.2007 Wiley-Liss, Inc.Key words: cetacea; sirenia; pinnipedia; carnirora; desmostylia; feeding ecology; aquatic adaptation A recurrent theme in tetrapod evolution is a return to an aquatic habitat. Whereas amphibians never quite parted with the water, all other tetrapod groups (reptiles, birds, and mammals) have several representatives that have returned to the water for at least an amphibious lifestyle of some degree, if not a fully aquatic existence. Mammals in particular have returned to the water in at least seven separate lineages (Cetacea, Sirenia, Desmostylia, Pinnipedia, Ursus maritimus [polar bear], Enhydra lutris [sea otter], and Thalassocnus spp. [aquatic sloths]). Some of these lineages have retained most of their terrestrial form while spending a great deal of time in the water, whereas others have changed their morphology dramatically and spend almost all, if not all, of their time in the water.Before exploring how the anatomical changes for life in water came about, one must know how marine mammals are related to one another, and particularly to their terrestrial relatives. A brief introduction to the phylogeny of each group of marine mammals is presented here, based on the latest studies using both morphological and molecular data. CETACEAN PHYLOGENYThe relationships of cetaceans to terrestrial mammals and other marine mammals was a great mystery for many

show abstract

Section: Discussionmentioning

confidence: 66%

Section: Sirenian Evolutionary Historymentioning

confidence: 99%

Evolution of marine mammals: Back to the sea after 300 million years

Uhen

2007

The Anatomical Record

163

113

View full text Add to dashboard Cite

show abstract

“…With the exception of two records of Miosireninae (Trichechidae) from the Late Oligocene of Westfalia and the Early Miocene of Belgium, only dugongids are known in the fossil record of Europe (see Domning, 1994;Sagne, 2001;C. Sagne, unpub.…”

Section: Discussionmentioning

confidence: 99%

“…Nat., Paris, 2001). The oldest and more basal sirenians (Prorastomus, Pezosiren) come from the early Middle Eocene of Jamaica and have been referred to the Prorastemidae (Savage, Domning & Thewissen, 1994;Domning, 2001), which is regarded as a paraphyletic taxon (Gheerbrant, Domning & Tassy, 2005). Sirenians probably diversified in the Early Eocene, paralleling the diversification of cetaceans in the Tethyan Realm, but so far there is no fossil known with certainty from Ypresian formations (see Zalmout, Ul-Haq & Gingerich, 2003).…”

Section: Introductionmentioning

confidence: 99%

New fossils of Sirenia from the Middle Eocene of Navarre (Western Pyrenees): the oldest West European sea cow record

et al. 2010

View full text Add to dashboard Cite

-Postcranial remains of Sirenia from the early Middle Eocene (late Lutetian) Urbasa-Andia Formation of Navarre (Western Pyrenees) are described. The material consists of two partial atlas vertebrae, one humerus and several dorsal ribs (from Arrasate, Urbasa plateau), and partial dorsal ribs (from Lezaun, Andia plateau). The morphology of the fossils is consistent with referral to Dugongidae, the only sirenian 2 clade known so far in the Middle Eocene of Europe. Moreover, the histological study of the ribs shows that the pachyosteosclerosis of extant Sirenia was definitively present by the early Middle Eocene. The oldest sirenian remains reported to date in the Pyrenean Realm were assigned to the Biarritzian, a regional stage that is currently adscribed either to the middle or to the lower-middle Bartonian. Therefore, the sirenian remains of Lezaun, reliably dated as late Lutetian (SBZ16 zone) in age, are definitively the earliest sirenian fossils known in Western Europe and are among the oldest sea cow record of Europe.

show abstract

“…Prorastomus from Jamaica is the most primitive fossil skull of a sirenian (Savage et al 1994). It has, surprisingly, five rather than the usual four premolars, which is presumably a secondary reversion rather than retention of the tooth formula of the Cretaceous ancestors of placentals.…”

Section: Sireniamentioning

confidence: 99%

The origin and evolution of mammals

2005

Choice Reviews Online

View full text Add to dashboard Cite

Fossil sirenia of the west Atlantic and Caribbean region. V. The most primitive known sirenian,Prorastomus sirenoidesOwen, 1855

Cited by 74 publications

References 20 publications

Evolution of marine mammals: Back to the sea after 300 million years

Evolution of marine mammals: Back to the sea after 300 million years

New fossils of Sirenia from the Middle Eocene of Navarre (Western Pyrenees): the oldest West European sea cow record

The origin and evolution of mammals

Contact Info

Product

Resources

About