For You Lot Data - Giant Flight Squirrel Fossil From A Barcelona Landfill Clarifies The Squirrel Identify Unit Of Measurement Tree

In 2002, a squad of scientists unearthed mysterious fossil remains inwards a landfill inwards Catalonia, Spain. At first, researchers supposed the unidentified fossil could live on a shape of primate.

Miopetaurista neogrivensis [Credit: Oscar Sanisidro]

"That expanse is really rich inwards fossils," said Oscar Sanisidro, paleontologist as well as scientific illustrator amongst the University of Kansas Biodiversity Institute as well as Natural History Museum. "The recovered specimen was unearthed yesteryear an excavator machine spell earthworks upwards a sector of the landfill. They could solely run across a duad of bones poking out from the dirt. They idea it mightiness live on a species of primate because of its limb proportions, perhaps Pliopithecus, a modest monkey institute inwards the area. Additionally, the presence of a lot of early on hominoids inwards the nearby deposits posed it every bit an fantabulous identify to await for those animals."

The training of the block, however, revealed the skull as well as other elements that identified it every bit a squirrel. Influenza A virus subtype H5N1 closer analysis institute the fossil possessed specialized wrist bones, unique to flight squirrels, that attach to a cartilaginous spur supporting a pare parachute. This parachute allows the rodents to glide downwards from trees upwards to distances of to a greater extent than than 400 feet.

"They were looking for primate remains -- as well as it turned out to live on a flight squirrel," Sanisidro said. "Flying squirrels don't genuinely fly. They accept a membrane inwards their limbs called a patagium that allows them to glide. You tin nation when a flight squirrel has the gliding apparatus based on the wrist bones -- i of the wrist bones, called pisiform, is where the patagium anchors as well as has a foreign twisted shape."

More than only a curiosity, the report only published inwards eLife shows the Barcelona landfill fossil to live on well-nigh 11.6 1000000 years sometime -- making the Miopetaurista neogrivensis specimen the oldest-known giant flight squirrel discovered.

Tree of life of squirrels, including the newly discovered specimen
[Credit: Isaac Casanovas/ICP]

Indeed, the honour redraws the evolutionary identify unit of measurement tree of squirrels, showing giant flight squirrels branched off from tree squirrels millions of years before than has been understood until now, somewhere betwixt 25 as well as 31 1000000 years ago. (Previous studies pegged the split upwards at well-nigh 23 1000000 years ago.) The researchers used the "molecular clock," or the typical charge per unit of measurement over fourth dimension that species' genomes undergo mutations, to calculate the fourth dimension when giant flight squirrels diverged from tree squirrels.

"When working amongst tree squirrels as well as flight squirrels, around of the features nosotros idea were unique to flight squirrels accept been institute yesteryear our squad inwards around non-flying squirrels," Sanisidro said. "Right now, nosotros don't accept features unique to flight squirrels except for the wrist. With fossils of micromammals, 99 percentage of the fourth dimension you're working amongst teeth. Wrist bones are extremely rare. But straightaway nosotros tin link those traits to the postcranial skeleton. Some of the flight squirrels institute inwards the yesteryear mightiness non live on flight squirrels because they mightiness accept had features mutual to other groups. Right now, nosotros accept confirmation amongst these features -- this is the oldest known giant flight squirrel."

Further, the Barcelona regain shows that today's giant tree squirrels accept undergone virtually no morphological alterations inwards the yesteryear 11.6 1000000 years. There has been thence petty change, inwards fact, the fossil institute inwards the landfill is almost indistinguishable of giant flight tree squirrels institute inwards Asia today.

"The i nosotros institute is similar a living fossil, because it's from the Miocene as well as it has the same characteristics every bit modern flight squirrels -- it has maintained the same anatomical features for a long time," Sanisidro said. "They are thence well-adapted to their ecosystems, they accept barely changed."

What the Miopetaurista neogrivensis' surround mightiness accept looked similar almost
12 1000000 years ago, only l kilometres away from Barcelona, Kingdom of Spain
[Credit: Oscar Sanisidro]

Living inwards a canopy forest, the giant flight squirrel was probable nocturnal similar the ones institute inwards Asia today.

"They're a really various group," said the KU researcher. "Some accept a high issue of insects inwards their diets; others consume fruits. Instead of leaves, around tree squirrels consume bark. The squirrels inwards our backyards consume nuts, around insects -- but flight squirrels are really diverse, as well as around accept really unique feeding strategies."

More than only the evolutionary history of squirrels, the fossil from Barcelona sheds lite on the natural history of the surround inwards Spain.

"Right now, the climate of that business office of Kingdom of Spain is to a greater extent than similar the i inwards California, but dorsum as well as thence at that topographic point were really unopen subtropical forests -- just the form of surround every bit inwards parts of Asia where nosotros accept living giant flight squirrels today," Sanisidro said. "That surround spread from Kingdom of Spain to Cathay at that indicate of the Miocene."

Source: University of Kansas [October 24, 2018]


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