This
tiny creature, covered in fur and reminiscent of a rat or a shrew, may
not look like much - but it's thought to be the earliest common ancestor
of all placental mammals.
Placental mammals give birth to live
young and get their name from the embryonic organ that nourishes
offspring in utero, the placenta (though scientifically they are known
as eutherians). The members of this diverse group range
from tiny mice to gargantuan whales to humans. There has been much
debate as to what the earliest placental mammal would have looked like,
or when it lived.
This new study provides the most complete
answer yet. The team used both morphological (analysing over 4,500
anatomical traits from living and extinct mammals) and molecular data
(DNA) and took six years to build their database. From this
record-breaking data collection, they have constructed an incredibly
detailed idea of this animal.
The common ancestor to placental
mammals was a small furry animal, likely weighing between 6 and 245
grams, that climbed trees and scampered along the ground. Its young were
born blind and hairless. It had three pairs of molars, ate insects and
possessed a highly folded brain. The study supports the appearance of
the first placental mammals occurring a few hundred thousand years after
the (non-avian) dinosaurs went extinct, around 65 million years ago.
For more on placental mammals: http://www.ucmp.berkeley.edu/
Image credit: Carl Buell.
http://www.livescience.com/
http://www.nature.com/news/
http://www.bbc.co.uk/news/
This
tiny creature, covered in fur and reminiscent of a rat or a shrew, may
not look like much - but it's thought to be the earliest common ancestor
of all placental mammals.
Placental mammals give birth to live young and get their name from the embryonic organ that nourishes offspring in utero, the placenta (though scientifically they are known as eutherians). The members of this diverse group range from tiny mice to gargantuan whales to humans. There has been much debate as to what the earliest placental mammal would have looked like, or when it lived.
This new study provides the most complete answer yet. The team used both morphological (analysing over 4,500 anatomical traits from living and extinct mammals) and molecular data (DNA) and took six years to build their database. From this record-breaking data collection, they have constructed an incredibly detailed idea of this animal.
The common ancestor to placental mammals was a small furry animal, likely weighing between 6 and 245 grams, that climbed trees and scampered along the ground. Its young were born blind and hairless. It had three pairs of molars, ate insects and possessed a highly folded brain. The study supports the appearance of the first placental mammals occurring a few hundred thousand years after the (non-avian) dinosaurs went extinct, around 65 million years ago.
For more on placental mammals: http://www.ucmp.berkeley.edu/
Image credit: Carl Buell.
http://www.livescience.com/
http://www.nature.com/news/
http://www.bbc.co.uk/news/
Placental mammals give birth to live young and get their name from the embryonic organ that nourishes offspring in utero, the placenta (though scientifically they are known as eutherians). The members of this diverse group range from tiny mice to gargantuan whales to humans. There has been much debate as to what the earliest placental mammal would have looked like, or when it lived.
This new study provides the most complete answer yet. The team used both morphological (analysing over 4,500 anatomical traits from living and extinct mammals) and molecular data (DNA) and took six years to build their database. From this record-breaking data collection, they have constructed an incredibly detailed idea of this animal.
The common ancestor to placental mammals was a small furry animal, likely weighing between 6 and 245 grams, that climbed trees and scampered along the ground. Its young were born blind and hairless. It had three pairs of molars, ate insects and possessed a highly folded brain. The study supports the appearance of the first placental mammals occurring a few hundred thousand years after the (non-avian) dinosaurs went extinct, around 65 million years ago.
For more on placental mammals: http://www.ucmp.berkeley.edu/
Image credit: Carl Buell.
http://www.livescience.com/
http://www.nature.com/news/
http://www.bbc.co.uk/news/
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