Glossary AMA - AMP
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AAC - ACR - ALE - AMA - AMP - ANH - AQU - ARC - ARS
AMARGASAURUS
(pronounced uh-MARG-uh-SAWR-us) Amargasaurus was a diplodocid sauropod
from the early Cretaceous Period, about 131 million-125 million years
ago. It was about 33 feet (10 m) long and weighed roughly 5000 kg. It
had a double row of spines along its neck, back, and tail.
AMBER
Amber is a yellowish, fossilized tree resin (from conifers) that sometimes
contains bits of trapped matter.
AMBULOCETUS
Ambulocetus natans (meaning: "walking whale that swims") is
an extinct mammal the size of a sea lion, 10 feet (3 m) long and about
650 pounds. Its limbs allowed it to swim and could also support it on
land. It had long, powerful jaws with shark-like teeth, a small brain,
and a pelvis fused to its backbone (like land-dwelling mammals but unlike
whales). It may have been an ancestor of the whales - it may have evolved
from animals like Mesonychid. Ambulocetus was found (in 1993) and named
(in 1994) by Hans Thewissen in Pakistan.
AMBLYDACTYLUS
Amblydactylus is a dinosaur known only from its fossilized footprints;
it is an ichnogenus. It was probably a hadrosaur, a duck-billed dinosaur.
Fossils of parallel tracks have been found in Canada, and are probably
evidence of herds of these dinosaurs.
AMEBELODON
Amebelodon, commonly known as a "Shovel Tusker," was a huge,
plant-eating mammal that lived in herds during the Early middle Miocene
(about 15 million years ago). This elephant-like browser had a shovel-shaped,
scoop-like lower jaw (mandible). This huge mouth had sharp teeth at the
front edge; these teeth were probably used for cutting leaves to eat.
Flat cheek teeth ground up the leaves. It also had 2 small, forward and
downward-pointing tusks toward the front of the upper jaw, probable used
for defense against predators. It lived in wet parts of prairies and ate
soft plants (including water plants). It was 20 ft (6 m) long, was 9 ft
(2.8 m) tall at the shoulder and weighed about 4.5 tons (4 tonnes). Fossils
have been found in North America. Classification: Order Proboscidea, Suborder
Elephantoidea, Family Gomphothere (closely related to Platybelodon).
Ammonite
Spiral-shelled molluscs, related to the modern day octopus and squid.
The soft body occupies the last chamber of the shell, the others are filled
with air to make it buoyant.
AMMOSAURUS
(pronounced AM-uh-SAWR-us) Ammosaurus (meaning: "sandy-ground lizard")
was a large, long-necked, small-headed, quadrupedal, plant-eating plateosaurid
prosauropod dinosaur from the early Jurassic Period, about 198 million
to 187 million years ago. It had a bulky body, small feet, big hands with
thumb claws and a long tail. It was about 14 feet (4 m) long, weighing
roughly 290 kg. Four incomplete skeletons (juvenile and adult) have been
found in Connecticut, Arizona, USA, and perhaps Nova Scotia, Canada. Ammosaurus
was named by paleontologist O. Marsh in 1891.
AMNIOTE
(pronounced AM-nee-oat) Amniotes are animals whose eggs contain an amnion,
a membrane that surrounds the embryo and helps retain fluids. This lets
an animal lay eggs other than in the water (without having them dry out).
Mammals, amphibians, birds, dinosaurs, turtles, and lizards are amniotes.
AMPELOSAURUS
(pronounced AM-pel-o-SAWR-us) Ampelosaurus (meaning: "vineyard lizard")
was a large, long-necked, small-headed, quadrupedal, plant-eating Titanosaurid
sauropod dinosaur from the late Cretaceous Period, about 198 million to
187 million years ago. It had a armored, bulky body, a long neck and a
long tail. It was about 50 feet (15 m) long. An incomplete fossil (including
dermal plates) was found in south-central France. Ampelosaurus was named
by paleontologist Le Loeuff in 1995. The type species is A. atacis.
Amphibian
The first air-breathing land vertebrates. Fossil evidence suggests that
they appeared around 360 million years ago in the late Devonian period.
Directly descended from fish, these creatures represent a transitional
stage between water dwellers and land dwellers. In the early stage of
their life amphibians have gills. These develop into lungs as they becomes
adults. The word "amphibian" comes from the Greek "amphi"
meaning both and "bios" meaning life. This is because the animal
can live both in and out of the water.
AMPHICOELIAS
(pronounced am-fee-SEEL-ee-yus) Amphicoelias (meaning: "double cavities")
was a diplodocid sauropod dinosaur. It was a long-necked, whip-tailed,
quadrupedal, plant-eater about 65 ft (20 m) long weighing roughly 100000
kg. Amphicoelias dates from the late Jurassic Period, about 150-140 million
years ago. Amphicoelias was named by paleontologist Cope in 1877. A single,
enormous fossilized vertebra of A. fragillium (8 ft = 2.4 m) was found
in Colorado, USA, but has since disappeared (based on Cope's description,
the animal that belonged to this fossil would have been 170 feet long).
A few other fossils were found belonging to the type species, A. altus.
Amphicoelias is a doubtful genus.
AMPHICYON
Amphicyon (meaning: "two dog"),also known as the bear-dog, was
probably the biggest land-dwelling carnivore of its time. This extinct
mammal about the size of a modern grizzly bear, about 6.5 ft (2 m) long.
(although it looked like a bear with wolf's teeth, it wasn't a bear).
It walked on four sturdy legs, had a short tail, thick neck. Amphicyon
ate meat and plants. This predator lived about 30 million years ago to
about 14 million years ago, during the mid-Tertiary. Fossils of Amphicyon
have been found in Europe (France and Germany) and North America (Nebraska,
USA). Classification: Class Mammalia, Order Carnivora, Family Amphicyonidae
(bear-dogs), Genus Amphicyon.