Monday, 24 November 2014

A fossil Pelican from the Latest Pliocene of Haryana State, India.

Pelicans are large aquatic Birds found on fresh, brackish and marine waters on every continent except Antarctica. They have fully webbed feet, and distinctive pouches beneath their bills, which help them to capture and swallow quite large prey. They have a fossil record dating back to the Oligocene, with representatives known from every continent they now inhabit. In the nineteenth century Sir Proby Thomas Cautley amassed a large collection of Pelican fossils from the Siwalik Hills in what was then British India. However the stratigraphic and geographic origins of the specimens are not well recorded (Cautly did not actually collect them himself) so it is unclear if the specimens date from the Miocene, Pliocene or even Pleistocene and whether they were excavated in modern India or Pakistan.

In a paper published in the journal PLoS One on 3 November 2014, Thomas Stidham of the Key Laboratory of Vertebrate Evolution and Systematics at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academyof Sciences, Kewal Krishan, Bahadur Singh and Abhik Ghosh of the Department of Anthropology at Panjab University and Rajeev Patnaik of the Department of Geology at Panjab University describe the discovery of a new Pelican fossil from Khetpurali in Haryana State in India.

The specimen comprises a single tarsometatarsus (lower leg bone – Bird fossils often consist only of leg or foot bones, as these are denser than other Bird bones), from the Tatrot Formation, dated to about 2.8 million years ago (i.e. the end of the Pliocene). The same section has previously produced Crocodile, Fish and Crab fossils, and has been interpreted as a floodplain pond environment.

Tarsometatarsus tentatively referred to Pelecanus sivalensis. (A) dorsal; (B) medial; (C) plantar; (D) lateral; (E) distal; and (F) proximal views. The arrow in (E) indicates the concave notch in the medial side of trochlea II that is a Steganopodes synapomorphy. The scale bar is 1 cm, with one scale bar for parts (A–D) and one for (E–F). Abbreviations: df—distal foramen; f—small pneumaticforamen; ie—intercondylar eminence; mc—medial crest of the hypotarsus; mf—fossa for metatarsal I; mr—ridge medial to the dorsal pneumaticforamen that is part of the extensor retinaculum attachment; pf—dorsal pneumatic foramen where the proximal foramina would be in other taxa;pl—lateral plantar opening of the proximal foramen; pm—medial plantar opening of the proximal foramen; r—ridge on the medial hypotarsal crestthat bounds a concave area to its medial side; tc—tendinal canal opening; tg—tendinal groove.Stidhamet al. (2014).

Two fossil Pelican species have previously been described from the Siwalik Hills, Pelecanus sivalensis and Pelecanus cautleyi. Unfortunately neither of these species are described from specimens that include the tarsometatarsus, making it impossible to assign the new specimen to species level, although it is thought likely to belong to the smaller species, Pelecanus sivalensis.

See also…

Galliform Birds (Pheasants, Chickens etc.) are a successful and widespread group today, with over 300 described species from around the world. Their fossil record dates back to the Early Eocene, when the first members of the group appeared in North America. Members of modern groups first appear in the Late Oligocene, and the group become particularly common in Pleistocene deposits. The earliest Galliformesare thought to have been closely related to the early Anserformes (Ducks and...

Birdlife International published an assessment of the conservation status of 350 newly described Bird Species for International Union for the Conservation of Nature's Red List of Threatened Species on 24 July 2014, the first such assessment by the organization...

The Phorusrhacid ‘Terror Birds’ were large, carnivorous flightless Birds that appear to have held the role of top terrestrial predators in South America throughout much of the Cenozoic. They are known to have colonized parts of North America, during the Great American...

Follow Sciency Thoughts on Facebook.

No comments:

Post a Comment