Glossary THE - TIM
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THECODONT
Thecodonts were socket-toothed reptiles, archosaurs that lived dring the
Triassic Period. They may have been the ancestors of dinosaurs, birds,
pterosaurs, and crocodilians. Chasmosaurus, pictured above, was a primitive
thecodont that lived during the early Triassic Period, about 250 million
years ago.
THECODONTOSAURUS
(pronounced THEE-co-DONT-oh-SAWR-us) Thecodontosaurus (meaning "socket-toothed
lizard") was a very early dinosaur from the late Triassic Period.
Thecodontosaurus ate plants and was about 7 feet (2.1 m) long. It had
a small head, large thumb claws, long legs, a relatively short neck, short
arms than legs, and a long tail. It could probably walk on two or four
legs, perhaps grazing and walking on all fours, but running on two legs.
It had blunt teeth with serrated edges. It had four toes on each leg and
five fingers on each hand. Fossils have been found in Britain, which was
probably dry and desert-like when Thecodontosaurus lived. Thecodontosaurus
is classified as a saurischian (a "lizard-hipped" dinosaur),
a sauropodomorpha (usually quadrupedal herbivores), a prosauropod (an
early, dead-end branch of the sauropodamorphas), and an Anchisaurid (the
earliest prosauropods).
THEORY
A theory is a proposed explanation for a phenomenon.
Therapsid
An order of mammal-like reptiles which were ancestral to the mammals.
They appeared in the Middle Permian period and became very diverse in
the Triassic before extinction in the Lower Jurassic period.
THERIZINOSAUR
(pronounced THER-uh-ZEEN-oh-sawrs) Therizinosaurs (meaning "scythe
lizards") were a family of strange theropod dinosaurs that had toothless
beaks and four toes on each foot. Some Therizinosaurs include Beipiaosaurus
(the most primitive therizinosaur), Therizinosaurus, Segnosaurus, Nanshiungosaurus,
Erlikosaurus, Enigmosaurus, Alxasaurus, and others.
THERIZINOSAURUS
(pronounced THER-uh-ZEEN-oh-SAWR-us) Therizinosaurus (meaning "scythe
lizard") was a huge, unusual theropod dinosaur known only from fossilized
arms with three enormous, sickle-like claws found in the southern Gobi
Desert in 1948. When it was found, it was thought to be a giant turtle,
not a dinosaur. Its classification is uncertain. The huge arms were 8
feet (2.45 m) long and the claws were 2 feet (60 cm) long. Some paleontologists
have speculated that these claws may have been used to rip open giant
termite nests, making Therizinosaurus an insectivore (an insect-eater),
but most think that it was an herbivore. Therizinosaurus lived during
the late Cretaceous Period (roughly 77-69 million years ago). Therizinosaurus
was named by the Russian paleontologist E. A. Maleev in 1954.
Theropod
A group of lizard-hipped dinosaurs. All theropods were bipedal carnivores
and ranged from the lightly built forms such as Coelophysis to the massive
Tyrannosaurus.
THEROSAURUS
Therosaurus is an invalid name for Iguanodon, a plant-eating dinosaur
with thumb spikes. It was about 33 feet (10 m) long and lived during the
early Cretaceous Period, roughly 130 to 110 million years ago.
THESCELOSAURUS
(pronounced THES-ke-loh-SAWR-us) Thescelosaurus (meaning "Marvelous
lizard") was a bipedal, plant-eating dinosaur whose fossilized, four-chambered
heart was found, perhaps indicating that it was warm-blooded. It dates
from the late Cretaceous Period, about 77 to 65 million years ago. It
had a small head, a bulky body, a long, pointed tail and short arms. It
was a thescelosaurid or hypsilophodontid, and an ornithischian dinosaur
about 12 feet (3.5 m) long and 3 feet (0.9 m) tall at the hips. Thescelosaurus
could probably run at about 30 mph (50 km/hr) for an extended time. Fossils
of Thescelosaurus, including skin impressions, have been found in western
North America. Thescelosaurus was named by paleontologist Gilmore in 1913.
The type species is T. neglectus.
THESPESIUS
(pronounced thes-PEES-ee-us) Thespesius (meaning "mighty one")
was a plant-eating dinosaur. This hadrosaur (duck-billed dinosaur) lived
during the late Cretaceous Period, roughly 65 million years ago. Fossil
were found in Nebraska and South Dakota, USA, North America. Only a few
vertebrae (back bones) and a foot bone were found. The type species is
T. occidentalis; it was named in 1856 by Joseph Leidy. Thespesius is a
nomen dubium.
Thrinaxodon
Thrinaxodon was a small cynodont, or mammal-like reptile about the size
of a cat. Its remains have been found in Late Triassic rocks in South
Africa. The skeleton has many characteristics of a reptile but the teeth,
with canines, molars, and incisors are typical mammalian features. Small
holes in the bone of the snout suggest whiskers and this in turn suggests
body hair, another mammalian characteristic.
Thrip
A very small insect that feeds on the sap of plants. It is white, yellow
or orange when young, but becomes brown or black with age. Its feeding
can cause damage to leaves and flowers
THYREOPHORA
(pronounced thii-RE-ah-FOR-ah) Thyreophorans (meaning "shield bearers")
were armored, plated, and/or spiked ornithischian dinosaurs that lived
from the early Jurassic to the late Cretaceous Period. These quadrupedal
(four-legged) plant-eaters included Scutellosaurus, Scelidosaurus, ankylosaurs
and stegosaurs.
TIBIA
The tibia is the shin bone - the bone in the lower, front part of the
leg between the knee and the ankle.
TICINOSUCHUS
(pronounced ti-SIEN-o-SOOK-us) Ticinosuchus (meaning "Tessin crocodile,"
named for the Tessin River) was an ancient rauisuchian (it was not a dinosaur,
but was a large-skulled archosaur). This meat-eating reptile walked on
four short legs and had a long tail. Ticinosuchus liced during the Triassic
period. Fossils have been found near the Tessin River, by Monte San Giorgio,
Canton Tessin, Switzerland, Europe. Fossilized trackways made by what
is called Chirotherium (which means "hand beast") were probably
those of Ticinosuchus. Ticinosuchus was named by Krebs in 1965.
TIANCHISAURUS
(pronounced TYAN-CHU-a-SAWR-us) Ticinosaurus nedegoapeferima (Ticinosuchus
means Lake Tian Chi (Heavenly Pool) lizard; nedegoapeferima is fragments
of the names of cast members of the movie Jurassic Park, Sam Neill, Laura
Dern, Jeff Goldblum, Richard Attenborough, Bob Peck, Martin Ferrero, Ariana
Richards and Joseph Mazzello). Steven Spielberg, the director of the movie
"Jurassic Park," donated money for Chinese dinosaur research,
so he was allowed to suggest its name. He chose Jurassosaurus nedegoapeferima,
which was later changed to Ticinosaurus nedegoapeferima (by paleontologist
Dong in 1993). Ticinosaurus was an armored, plant-eating dinosaur that
was about 10 feet 3 m) long. It lived during the middle Jurassic Period.
Fossils of this ankylosaurid were found in Xinjiang Province in northwestern
China. Ticinosaurus is a Nomen Nudum.
Timimus
Timimus was a small, 3m, bipedal, meat-eating ornithomimid dinosaur. It
comes from the Early Cretaceous period in what is now Australia.