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Roger Weller,
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Glyptodont
Jocelynn Snoozy
Historical
Geology
Spring 2005
Glyptodont
The glyptodont was a prehistoric mammal the size of a
small car. It had a large shell,
resembling that of a turtle and a long armored tail. “Some of the glyptodonts, such as Doedicurus, had an armored tail which
ended in a viciously spiked club, a weapon of defense similar to that possessed
by the ankylosaurs” (Norman, 190).
Description
The glyptodont was
armored from nearly head to toe.
Its head had a small cap of armor and its tail
was
enrobed in a tube of
armor plating. “The skulls of
glyptodonts were very
deep, and housed extremely
powerful muscles which
allowed these animals to
grind up abrasive
grasses.” The teeth used for
grinding up plant
matter were open-rooted so that
they continued to grow
despite being worn down by eating abrasive materials. The glyptodont was a placental mammal,
meaning that it developed inside the mother’s uterus and was born almost fully
developed. Although these animals were
extremely large, the glyptodont was most likely gentle because it was an
herbivore. Its large spiked tail was
used for protection against saber-tooth tigers.
It may have also been used in mating practices as two males fight over a
female (Moss, par. 15).
There has been question as to whether
the force of the glyptodont’s tail may have been enough to produce the large
cracks found in some fossil remains of their shells. Researchers at the
This drawing depicts what an ancient glyptodont
looked like.
Edentates
The glyptodont belongs to an animal group called
edentates, which means “toothless.” This
name is actually misleading. All of the
members of this group have teeth except for the anteater. Another name given to this group is
xenarthrans, which means “strange joint.”
This term is used to describe the group’s unusual backbones. According to “Successful in Spite of
Themselves,” an article written for Natural History, “In most mammals,
the paired overlapping surfaces that prevent dislocation between vertebrae are
flat or faintly curved, but in these animals, the surfaces are scrolled into an
elaborate set of interlocking ridges and valleys.” This was to help the glyptodont carry such a
large and heavy shell (“Successful,” par. 4 &5).
First
Appearance and Location
The edentates developed following
the extinction of the dinosaurs, emerging about three million years ago (Moss,
par. 1). “Among the edentates were
armadillos, which first appeared during the Paleocene,” explains author David
Norman. “During the more recent Pliocene
and Pleistocene Epoch,” the glyptodonts appeared (
The edentates were almost
entirely confined to South America until the “Panamanian isthmus reconnected
North and
Darwin’s Expedition
Darwin found shells and bones in a
sand bank while exploring a bay on his trip on the HMS Beagle. He had the fossils shipped to
Extinction
The glyptodont became extinct 10,000
years ago (“Successful,” par. 10) during the most recent Ice Age. It was one of the three-fourths of the large
mammals to disappear in North America and one of the four-fifths of them to
become extinct in South America (
Modern Descendants
Armadillos, or armored pigs are the
most closely related species of the glyptodont.
They too, have armored plating covering almost their entire bodies, but
the modern armadillo is much smaller than the large glyptodont. Most of the early armadillos died out,
leaving about 20 species on Earth today, all of which are in
The modern armadillo has been
nicknamed the “armored pig” because it changed its food preference from only
plants to almost anything. It is now a
carnivore, feeding on insects, “small lizards, salamanders, snakes, frogs, and
toads” (Smith, par. 13). The armadillo
is becoming more versatile to climate changes and has been increasing its
resistance to colder temperatures every year (Haines, 201).
Glyptodont Links
Some
quick information: http://www.biologydaily.com/biology/Glyptodon
Lifelike
figurine photo: http://dinofarm.com/glyptodon.html
Glyptodont
Photo: http://prehistoricsillustrated.com/pg_kc_10.html
Link
to various glyptodont facts: http://www.bbc.co.uk/nature/wildfacts/factfiles/3005.shtml
Skull
replica photo: http://www.skullsunlimited.com/fossil-glyptodont.html
Glyptodont
shell fossil: http://www.indiana9fossils.com/Vertebrates/Glyptodont.htm
Glyptodont
scale samples: http://bassexpert.com/fossil/FossilPages/GlyptodontScales.htm
Glyptodont
Info: http://www.savvycenter.com/explorer/news/glypto.htm
Glyptodont
fossil photos: http://www.fossilexpeditions.com/armad.htm
Information
on Pleistocene animals: http://www.richland2.k12.sc.us/rce/Websites/fossils.htm