DISAMPING KANAN INI.............
PLEASE USE ........ "TRANSLATE MACHINE" .. GOOGLE TRANSLATE BESIDE RIGHT THIS
.....................................
Landak dan tapir kuno pernah huni British Columbia
Ancient hedgehog and tapir once inhabited British Columbia
Date:
July 8, 2014
Source:
Society of Vertebrate Paleontology
Summary:
A new study describes an ancient hedgehog and tapir
that lived in what is now Driftwood Canyon Provincial Park, British Columbia,
approximately 52 million years ago. The ancient hedgehog is a species hitherto
unknown to science.
................................
The Earth has experienced many dramatic changes in climate
since the dinosaurs went extinct 66 million years ago. One of the warmest
periods was the early Eocene Epoch, 50 to 53 million years ago. During this
interval, North American mammal communities were quite distinct from those of
today. This is illustrated by a study published in the latest issue of the Journal of Vertebrate Paleontology
that describes an ancient hedgehog and tapir that lived in what is now
Driftwood Canyon Provincial Park, British Columbia, some 52 million years ago.
"Within
Canada, the only other fossil localities yielding mammals of similar age are
from the Arctic, so these fossils from British Columbia help fill a significant
geographic gap," said Dr. Natalia Rybczynski of the Canadian Museum of
Nature, a co-author of the study. Other fossils of this age come from Wyoming
and Colorado, some 2,700 miles to the south of the Arctic site of Ellesmere
Island.
The ancient
hedgehog is a species hitherto unknown to science. It is named Silvacola
acares, which means "tiny forest dweller," since this minute hedgehog
likely had a body length of only 2 to 2.5 inches. The delicate fossil jaw of
Silvacola was not freed from the surrounding rock as is typical for fossils.
Rather, it was scanned with an industrial, high resolution CT (computed
tomography) scanner at Penn State University so it could be studied without
risking damage to its tiny teeth. Modern hedgehogs and their relatives are
restricted to Europe, Asia, and Africa.
The other
mammal discovered at the site, Heptodon, is an ancient relative of modern
tapirs, which resemble small rhinos with no horns and a short, mobile, trunk or
proboscis.
"Heptodon
was about half the size of today's tapirs, and it lacked the short trunk that
occurs on later species and their living cousins. Based upon its teeth, it was
probably a leaf-eater, which fits nicely with the rainforest environment
indicated by the fossil plants at Driftwood Canyon," said Dr. Jaelyn
Eberle of the University of Colorado, lead author of the study.
Most of the
fossil-bearing rocks at Driftwood Canyon formed on the bottom of an ancient
lake and are well-known for their exceptionally well-preserved leaves, insects,
and fishes. But no fossils of mammals had ever before been identified at the
site. The fieldwork that resulted in these discovered was supported by Natural
Sciences and Engineering Research Council of Canada.
"The
discovery in northern British Columbia of an early cousin to tapirs is
intriguing because today's tapirs live in the tropics. Its occurrence,
alongside a diversity of fossil plants that indicates a rainforest, supports an
idea put forward by others that tapirs and their extinct kin are good
indicators of dense forests and high precipitation," said Eberle.
Fossil plants
from the site indicate the area seldom experienced freezing temperatures and
probably had a climate similar to that of Portland, Oregon, located roughly 700
miles to the south.
"Driftwood
Canyon is a window into a lost world -- an evolutionary experiment where palms
grew beneath spruce trees and the insects included a mixture of Canadian and
Australian species. Discovering mammals allows us to paint a more complete
picture of this lost world," said Dr. David Greenwood of Brandon
University, a co-author of the study. "The early Eocene is a time in the
geological past that helps us understand how present day Canada came to have
the temperate plants and animals it has today. However, it can also help us
understand how the world may change as the global climate continues to
warm."
Story
Source:
The above
story is based on materials provided by Society of Vertebrate Paleontology. Note: Materials may be edited
for content and length.
Journal
Reference:
- Eberle, J.J., N. Rybczynski, and D.R. Greenwood. Early Eocene mammals from the Driftwood Creek beds, Driftwood Canyon Provincial Park, northern British Columbia. Journal of Vertebrate Paleontology, 2014; 34 (4): 739-746
