Researchers have long puzzled over when monkey arrived on the North American continent from South America . Now , an psychoanalysis of seven fossilize teeth reveal along the shore of the Panama Canal let out that rascal were present in Central America – the southernmost part of the North American landmass – much in the first place than we thought . CalledPanamacebus transitus , this new species is the first North American fossil monkey , and it ’s described inNaturethis calendar week .
rapscallion likely dispersed from Africa across the Atlantic to South America by “ rafting ” on floating island some 34 to 37 million years ago . Such an musical theme has come in for a lot of criticism before , but it seems to be the only manner to explain the scatter of monkeys . theory indicate that vast blankets of vegetation , over with Sir Herbert Beerbohm Tree acting as sails ( by nature , not tack by the monkeys ) could have permit them to cover the Atlantic in as little as14.7 day .
today , New World scalawag ( called the platyrrhinian ) are found throughout tropical forests in both North and South America . But the two Continent were separated by an sea until only 3 to 4 million year ago when the Isthmus of Panama bring together them together . Previous molecular study suggested that New World monkeys did n’t come in Central America until around that same fourth dimension . However , because of the everlasting absence of primate fossils from Central America , their other evolutionary history in the tropic was still a mystery .
In 2009 , an expansion of the Panama Canal exposed fossil - bearing rock , and further fieldwork conduce by Jonathan Bloch from the University of Florida , Gainesville uncovered seven fossilized teeth from a 20.9 - million - year - sure-enough ash layer in the Las Cascadas Formation of the Panama Canal Basin .
Not only are these the first dodo monkey discovered on the North American land mass , they ’re also the earliest grounds we have for the motility of mammal between North and South America . Until now , the old grounds for mammal interchange between the two continents were sloth fogey dating back 8.5 to 9 million yr .
These new findings suggest that New World monkeys diversified into the five kinfolk we see in the tropics today around 22 to 25 million years ago : Callitrichidae , Cebidae , Aotidae , Pitheciidae , and Atelidae . This timing fits with recent tectonic reconstructions of the Central American Seaway during the early part of the Miocene Epoch ( which spans 23.8 to 5.3 million class ) . Furthermore , the fossils show that New World monkeys were already distributed around the Caribbean by that time .
Panamacebus transituswas a medium - sized imp weighing about 2.7 kilograms ( 5.9 pounds ) . The genus name combines “ Panama ” with “ Cebus , ” the same root as Cebidae , one of the five family of New World scallywag . It ’s think to be closely relate to a living appendage of the genusCebus , the capuchin monkey ( pictured to the right hand ) . The new coinage name total from “ transportation system ” and refers to its dispersal from South to North America during the early Miocene .
According to the researcher , northward movement after that time was in all probability confine more by difference in the ecological factors of North and South American forests than by geographical barrier and climate differences .
Las Cascadas locality where Panamacebus was found . Jason Head
Image in text : The upper molar of Panamacebus . Aldo Rincon
