Glossary ARC - ARR
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AAC - ACR - ALE - AMA - AMP - ANH - AQU - ARC - ARS
ARCHAEOTHYRIS
Archaeothyris is the oldest-known pelycosaur. This long-tailed quadruped
lived in warm, humid forests of the early-mid Pennsylvanian period, about
300 million years ago. Archaeothyris looked sperficially like a lizard
and was about 20 inches (50 cm) long. This carnivore (meat-eater) had
strong jaws and sharp, pointed teeth; it may have eaten small reptiles
like Hylonomus. Fossils have been found in Nova Scotia, North America.
Clasification: Subclass Synapsida, Order Pelycosauris, Family Ophicodontia.
Archelon
A carnivorous sea turtle of the Cretaceous period which grew to be about
the size of a car.
ARCHILLOBATOR
Achillobator (Achilles was a Greek hero with a vulnerable heel tendon
and bator is Mongolian for hero) was an advanced meat-eating dinosaur
that was about 16 ft (5 m) long. This large dromaeosaur (deinonychosaur)
has a sickle-shaped claw on each foot. This theropod lived during the
late Cretaceous period A. giganticus.
ARCHIMEDES
Archimedes was a corkscrew-shaped colonial genus of bryozoan named for
the ancient Greek Archimedes, who invented the water screw (the bryozoan
looks like the water screw). The marine bryozoan Archimedes were tubular-shaped
zooids with calcified walls. They lived in colonies during the Carboniferous,
roughly 360 to 280 million years ago. Classification: Kingdom Animalia,
Phylum Bryozoa, Class Stenolaemata, Order Fenestrida, Family Fenestellidae,
Genus Archimedes, many species.
Archipelago
A group of many islands.
ARCHITEUTHIS
(pronounced ark-ee-TOO-this) Architeuthis is the giant squid. It is the
largest squid and the largest invertebrate (animal without a backbone),
but it has never been seen since it lives very deep in the oceans. The
largest-known Architeuthis was 57 feet (17.5 m) long. It has eight arms,
two longer feeding tentacles, a beak, a large head, and two eyes larger
than basketballs! These soft-bodied cephalopods are fast-moving carnivores
that catch prey with their tentacles, then poison it with a bite from
beak-like jaws. They move by squirting water through a siphon, a type
of jet propulsion. Only dead examples of Architeuthis have been found.
Its only enemy is the sperm whale who hunts it deep in the ocean.
Archosaur
Literally "ancient reptiles". These include the thecodonts or
socket-toothed reptiles, which in turn gave rise to the pterosaurs, crocodiles,
dinosaurs and birds.
ARCTOSAURUS
(pronounced ARK-toh-SAWR-us) Arctosaurus meaning: "arctic lizard"
was a meat-eating dinosaur that lived during the late Triassic Period.
This theropod was about 10 feet (3 m) long. Fossils of Arctosaurus were
found in Canada. Arctosaurus was described in 1875 by Adams. The type
species is A. osborni, but Arctosaurus is nomen dubium (only neck vertebrae
have been found and it may or may not even be a theropod).
ARGENTINOSAURUS
(pronounced ahr-gen-TEEN-oh-SAWR-us) Argentinosaurus huinculensis was
a 130-140 feet (40-42 m) long titanosaurid sauropod. It was an enormous,
long-necked, long-tailed, quadrupedal, plant-eater from Argentina, South
America during the Cretaceous Period. Argentinosaurus, meaning: "Argentina
Lizard," was named by paleontologists Coria and José Bonaparte in
1993. It is known from fossilized back vertebrae, tibia, ribs and sacrum.
It may be the largest dinosaur.
ARGYROSAURUS
(pronounced AHR-ji-ro-SAWR-us) Argyrosaurus (meaning: "silver lizard")
was a large plant-eating dinosaur about 70 ft (21 m) long weighing roughly
20000 kg. This massive quadruped. Some limbs have been found in Argentina
and Uruguay. It dates from the late Cretaceous Period, about 73-65 million
years ago. This sauropod, perhaps an armored titanosaurid, was named by
Lydekker in 1893. The type species of this doubtful genus is A. superbus.
ARISTOSAURUS
(pronounced uh-RIST-uh-SAWR-us) Aristosaurus is an invalid name for Massospondylus,
an herbivore Saurischian dinosaur from the late Triassic Period.
ARISTOSUCHUS
(pronounced uh-RIST-uh-SUE-kus) Aristosuchus (meaning: "best lizard")
is an old (invalid) name for Calamospondylus. It was a bipedal, meat-eating
theropod dinosaur with large hand claws. This coelurosaur dates from the
early Cretaceous Period, about 125 million years old. This predator was
perhaps 6.5 ft (2 m) long, weighing about 65 pounds (30 kg).
ARKANSAURUS
(pronounced AHR-kan-SAWR-us) Arkansaurus (meaning: "Arkansas lizard")
was a bird-like, bipedal, meat-eating dinosaur (a theropod) that lived
during the late Cretaceous Period. (It is a coelurosaur and perhaps an
ornothimimid.) This dinosaur is known from foot bones found in Arkansas,
USA. Fossilized foot bones and claws were found in 1972 by J. B. Friday
while looking for a lost cow on his farm near Lockesburg, Arkansas, USA.
Arkansaurus was informally named and described by the geologist James
Harrison Quinn in 1973, but this dinosaur has not been formally described
(hence it is a nomen nudum). The type species is A. fridayi (the species
name honors J.B. Friday, who found the fossil and donated it to the University
of Arkansas).
ARRHINOCERATOPS
(pronounced aye-RYE-no-SER-uh-tops) Arrhinoceratops (meaning: "without
nose-horn face") was a ceratopsian dinosaur about 20 feet (6 m) long,
weighing roughly 3540 kg. It was a frilled, horned, plant-eater from the
late Cretaceous Period, about 72 million-68 million years ago. It is known
from a skull found in Alberta, Canada. It was named by paleontologist
Wm. A. Parks in 1925. The type species is A. brachyops.