More Than 50 MYA, Tapir, Rhino Ancestors Endured 6 Months Of Darkness In Then-Tropical Arctic Basin

[hatrack]

Ancestors of tapirs and ancient cousins of rhinos living above the Arctic Circle 53 million years ago endured six months of darkness each year in a far milder climate than today that featured lush, swampy forests, according to a new study led by the University of Colorado at Boulder.

CU-Boulder Assistant Professor Jaelyn Eberle said the study shows several varieties of prehistoric mammals as heavy as 1,000 pounds each lived on what is today Ellesmere Island near Greenland on a summer diet of flowering plants, deciduous leaves and aquatic vegetation. But in winter's twilight they apparently switched over to foods like twigs, leaf litter, evergreen needles and fungi, said Eberle, curator of fossil vertebrates at the University of Colorado Museum of Natural History and chief study author.

The study has implications for the dispersal of early mammals across polar land bridges into North America and for modern mammals that likely will begin moving north if Earth's climate continues to warm. A paper on the subject co-authored by Henry Fricke of Colorado College in Colorado Springs and John Humphrey of the Colorado School of Mines in Golden appears in the June issue of Geology.

The team used an analysis of carbon and oxygen isotopes extracted from the fossil teeth of three varieties of mammals from Ellesmere Island - a hippo-like, semi-aquatic creature known as Coryphodon, a second, smaller ancestor of today's tapirs and a third rhino-like mammal known as brontothere.

EDIT

http://www.terradaily.com/reports/53_Million_Year_Old_High_Arctic_Mammals_Wintered_In_Darkness_999.html

[kestrel91316]

1. Given the movement of tectonic plates, are they sure that the land there

was "there" back then? Could it have sat farther south and had longer daylight?

[Javaman]

2. recent findings have found that it was actually located in what is now

present day Miami. The findings are supported by fossilized bone hula mugs.

[happyslug]

3. Last 130 million years North America Plate has been moving Westward

So the location of much of North America has been more or less the same latitude over the last 130 million years (Longitude is other wise, consistently change westward compared to Europe).

http://www.google.com/imgres?imgurl=&imgrefurl=http://earthscienceaaron.blogspot.com/2008/09/uhhplate-tectonics.html&h=600&w=504&sz=66&tbnid=IldzYldnVkJREM:&tbnh=135&tbnw=113&prev=/images%3Fq%3DPlate%2Btectonics%2Bmovement&hl=en&usg=__-Bjn9VpD7bo3CNaPM5Dqn11wvaU=&ei=mOArStLcLeCntgeM9ZSxCA&sa=X&oi=image_result&resnum=2&ct=image

http://upload.wikimedia.org/wikipedia/commons/8/8a/Plates_tect2_en.svg
http://en.wikipedia.org/wiki/Plate_tectonics

http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Continents.shtml