2009-04-23 – Puijila darwini: Anello mancante nell`evoluzione dei Pinnipedi (missing link in pinniped evolution)

recommended links:

http://nature.ca/puijila/index_e.cfm (Official home page)

http://www.eurekalert.org/pub_releases/2009-04/cmon-feo042009.php (good scientific description of the discovery)

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 Fossil of a walking seal found

Remains of a previously unknown mammal could represent a missing link in pinniped evolution

By Solmaz Barazesh

Web edition : Wednesday, April 22nd, 2009 

Researchers discovered remains of a previously unknown pinniped in the Canadian Arctic. (Inset shows bones that were found.) The fossilized skeleton was about 65 percent complete. (Illustration fills in the missing pieces.)

A fossilized skeleton of what researchers are calling a walking seal has been uncovered in the Canadian Arctic. The remains of this previously unknown mammal could shed light on the evolution of pinnipeds, the group that includes seals, sea lions and walruses, researchers report in the April 23 Nature.

The animal, named Puijila darwini, had a long tail and an otterlike body with webbed feet and legs like a terrestrial animal, the researchers report. But P. darwini also had a pinniped-like skull.

“We realized there was no way this was an otter,” says study coauthor Natalia Rybczynski of the Canadian Museum of Nature in Ottawa. The walking seal probably lived about 20 million years ago and was adept at moving both on land and in water, the team reports. 

 

Researchers describe Puijila darwini (illustration shown) as a walking seal, with the legs of a terrestrial animal, a seal-like skull and webbed feet.

 Scientists had theorized that pinnipeds evolved from land-dwelling ancestors but had little fossil evidence to support that claim. The new finding could be the missing link in pinniped evolution, the researchers report.

“This is a fantastic discovery,” comments evolutionary biologist Annalisa Berta of San Diego State University.

The finding may also indicate that the Arctic was a geographic center for pinniped evolution, the researchers speculate.

But, Berta notes, other early pinnipeds have been discovered in the North Pacific and Eurasia. “We can’t yet conclude the Arctic was the area of origin for pinnipeds,” Berta says.

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Jakarta Post

Otter-like fossil reveals early seal evolution

The Associated Press – ‎22-apr-2009‎

One expert called it “a fantastic discovery” that fills a crucial gap in the fossil record. The 23 million-year-old creature was not a direct ancestor of …

Walking Seal Called Missing Link in Evolution FOXNews

Otter-Like Fossil Is a Missing Link in Seal Evolution Discover Magazine

Science Now  – Times Online  – CTV.ca  – Science News

tutte le notizie (193) »

2008-10-15 – Texas, USA: Rifugio per mammiferi fossili (Eocene, mammals, Diablomomys dalquesti)

Nuovi resti fossili testimoniano la permanenza di mammiferi in Texas nell Eocene in un periodo di “stress climatico”

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New Fossil Reveals Primates Lingered in Texas; Climate Provided Refuge for Diminishing Population

October 13, 2008

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AUSTIN, Texas — More than 40 million years ago, primates preferred Texas to northern climates that were significantly cooling, according to new fossil evidence discovered by Chris Kirk, physical anthropologist at The University of Texas at Austin.

 

Kirk and Blythe Williams from Duke University have discovered Diablomomys dalquesti, a new genus and species of primate that dates to 44-43 million years ago when tropical forests and active volcanoes covered west Texas.

The researchers have published their discovery in the Journal of Human Evolution article, “New Uintan Primates from Texas and their Implications for North American Patterns of Species Richness during the Eocene.”

During the early part of the Eocene epoch, primates were common in the tropical forests that covered most of North America. Over time, however, climatic cooling caused a dramatic decline in the abundance and diversity of North American primates. By the end of the Eocene, primates and most tropical species had almost disappeared from North America.

Kirk’s discovery of late middle Eocene (Uintan) primates at the Devil’s Graveyard Formation in Southwest Texas reveals new information about how North American primates evolved during this period of faunal (animal) reorganization.

“After several years of collecting new fossils, reviewing Texas’ primate community and comparing it to other places in North America, we found a much more diverse group of primate species in Texas than we expected,” Kirk said. “It seems that primates stuck around in Texas much longer than many other parts of the continent because the climate stayed warm for a longer period of time. While primate diversity was falling off precipitously in places like Utah and Wyoming during the late middle Eocene, west Texas provided a humid, tropical refuge for primates and other arboreal (tree-inhabiting) animals.”

The anthropologists named the new primate Diablomomys dalquesti, combining “Diablo” to represent the Devil’s Graveyard Formation (sand- and mudstones near Big Bend National Park) with Omomys, a related fossil genus. The dalquesti species name honors Walter and Rose Dalquest, who donated the land on which the fossil was collected (Midwestern State University’s ‘Dalquest Research Site’). Walter was a Texas paleontologist and distinguished biology professor at Midwestern State University in Wichita Falls until his death in 2000.

For more information, contact: Christian Clarke Casarez, Office of Public Affairs, 512-471-4945; Chris Kirk, assistant professor, Department of Anthropology, 512-471-0056 (office), 512-636-2634 (cell).

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• Most Ancient Case of Tuberculosis Found in 500,000-Year-Old Human; Evidence Suggests Vitamin D Deficiency Endangers Migrating Populations
       December 7, 2007

source: http://www.utexas.edu/news/2008/10/13/fossil_primates/

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update 2008-10-21 11:23 Italy

Environment News Service

Fossil Reveals Ancient Primates Took Refuge in Texas Environment News Service – 59 minuti fa AUSTIN, Texas, October 20, 2008 (ENS) – More than 43 million years ago, when tropical forests and active volcanoes covered west Texas, primates chose to …

2008-10-09 – Nuovi paleo-video dai Blogs (Videos, 3D reconstructions, crazy Paleontologists)

Sui blog, da poco pubblicati nuovi video:

Blog GER – Fossilien-news

• Kanal “Homotherium” zeigt Raubkatzen-Videos Ottobre 7, 2008

       (Two videos with 3d reconstruction of: Panthera leo spelaea and Megantereon)

Blog ENG – Palaeoblog 

• Fun In The Currie Lab Ottobre 8, 2008

      (crazy Paleontologist of Phil Currie’s Labs filmed by one of the grad students, Miriam Reichel)

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2008-09-25 – Resti fossili del Pleistocene scoperti a Ortona

PALEONTOLOGIA: A ORTONA SCOPERTI RESTI ANIMALI DEL PLEISTOCENE

Ippopotami, elefanti, cervi abitavano a Ortona, sulle sponde dell’Adriatico, 700.000 di anni fa. Questa eccezionale scoperta verra’ illustrata nel convegno e nella mostra “Il giacimento paleontologico di Ortona: la costa abruzzese 700.000 anni fa” in programma il 27 settembre alle 9,00 nel Museo Geopaleontologico di Palena (www.museogeopaleontologicopalena.it) (Chieti), nell’ambito delle iniziative delle Giornate europee del Patrimonio, organizzate dalla Soprintendenza per i Beni Archeologici dell’Abruzzo. I restauri dei reperti faunistici e le ricerche sul giacimento paleontologico della citta’ adriatica, in localita’ Ciampino, sono stati condotti dal Servizio Geologico e Paleontologico della Soprintendenza per i beni archeologici dell’Abruzzo in collaborazione con il Dipartimento di Scienze della Terra dell’Universita’ di Firenze. Le ricerche scientifiche hanno evidenziato un’associazione faunistica a mammiferi riconducibile alla fasi iniziali del Pleistocene, all’incirca 700.000 anni fa e consentono la ricostruzione paleogeografica della zona costiera, delle colline e dei fiumi abruzzesi, mostrando ambienti ed ecosistemi particolari: ampie valli alluvionali spesso confinate da zone palustri, foci caratterizzate da lagune e dune. E’ da questo contesto che provengono i reperti di ippopotami,elefanti,cervi che abitavano anticamente in riva all’Adriatico, allargando il panorama delle conoscenze sulla geodiversita’ e biodiversita’ del passato in Abruzzo. L’iniziativa ha il patrocinio della Commissione Italiana per l’ “International Year of Planet Earth” (Anno Internazionale del Pianeta Terra) proclamato dall’ONU nel 2005 e si inserisce nelle manifestazioni culturali e scientifiche proposte nel mondo per il triennio 2007-2009. (AGI)

(25 settembre 2008 ore 15.50)

link: http://ilcentro.repubblica.it/dettaglio-news/Chieti-15:50/3327519?edizione=Chieti

Tracce fossili di escavazione nel Triassico dell’Antartide

Articolo tratto da www.hindu.com (link):

Pre-dinosaur era burrows discovered in Antarctica

New York (PTI): Paleontologists have discovered pre-dinosaur era burrows in Antarctica, which they claim were probably dug up by tetrapods — any land vertebrates with four legs — about 245 million years ago. The largest burrow is about 35 centimetres long and six centimetres wide — it was preserved when a flood washed sand into it.

Though no animal remains were found inside the burrow casts, the hardened sediment in each burrow preserved a track made as the animals entered and exited, according to the paleontologists. “In addition, scratch marks from the animals’ initial excavation were apparent in some places. We have got evidence that these burrows were made by land-dwelling animals rather than crayfish,” Christian Sidor of Washington University, who led the team, said.

Despite the absence of fossil bones, the burrows’ relatively small size prompted the US team to speculate that their owners might have been small lizardlike reptiles called Procolophonids or an early mammal relative called Thrinaxodon.