Smithsonian Institution Dinosaur Museum/DINOSAUR_MUSEUM.ISO/pc/mswin/archives/diction.r-z

Text File | 1994-08-06 | 13KB | 424 lines

RADIUS:  One of the two long bones of
the lower arm.  It allows the arm to be
rotated about its long axis by
articulating with the ulna.

RECURVED:  Curved backward or
inward, as in teeth.

REPTILES:  Vertebrate animals with
skins made of scales of horn, and no
free-living larval stage.  They hatch in a
miniature adult stage from eggs laid on
dry land.

RESONATOR:  A device which reinforces
or causes prolongation of sound by
vibrating in concert with the source of
the sound.

RIGOR MORTIS:  The stiffening of the
body muscles following death.

ROSTRAL BONE:  The beak-like bone
found at the tip of the upper jaw, but
only in ceratopSian dinosaurs.
SACRALS:  The vertebrae that fuse the
backbone to the pelvis.  In most
dinosaurs there are five to ten sacrals.
The ilia are the pelvic bones that fuse
with the sacrals.

SACRUM:  (SAY-krumm)  A composite
bone formed by the fusion of vertebrae,
and forming the dorsal part of the
pelvis.

SAURISCHIA:  One of the two clades of
dinosaurs.  It includes the taxa
THEROPODA (the flesh-eaters) and
SAUROPODOMORPHA (the sauropods,
and prosauropods and their relatives).

SAUROPODA:  "Reptile Feet."  This clade
is the group of classic herbivorous
"brontosaurus-like" dinosaurs, and is
formed by the brachiosaurids,
camarasaurids, cetiosaurids,
diplodocids, euhelopodids, shunosaurids,
titanosaurids, and vulcanodontids.

SAUROPODS:  Vernacular for members
of the Sauropoda.

SAVANNA:  A wide open plain of tall
grasses in a tropical region,
interspersed with trees and shrubs.  The
plants are able to survive a hot, dry
season of considerable length.

SCAPULA:  The shoulder blade.

SCLEROTIC RING:  A ring made of flat,
plate-like bones in the eyeball.  Shaped
like a pineapple slice, this ring helps to
maintain the eyeball's shape.

SCUTELLOSAURUS:  [scoo-Tell-oh-
SOAR-uss]  "Small-Bony Plate Reptile."
Early Jurassic, ornithopod dinosaur up
to 53 inches in length.  Quadrupedal
herbivore, which had hundreds of bony
knobs in its skin.  Found in Arizona.

SERRATED:  Having jagged or notched
projections like saw teeth.

SILURIAN:  Silurian Period:  A unit of
geologic time.  A period within the
Paleozoic Era which occurred from about
439 million to 409 million years ago.
After the Ordovician extinction, there
was an evolutionary recovery of many of
the decimated taxa.  The broad, shallow
seas of the Silurian teemed with life.  In
the tropics, a diverse community of
marine organisms built reefs larger than
any than any earlier ones.  More
advanced predators were in the oceans,
including the first jawed fishes.  Land,
which had been devoid of living things
until this time, was conquered by plants,
then animals, in quick succession at the
close of the period.

SPECIES:  A taxonomic category in
Linnaean biological classification.  In
biology, a subdivision of a Genus and
composed of a grouping of organisms of
a population which is capable of
interbreeding and producing viable
offspring, and is reproductively isolated
from other such groups.  The same
word, species, is used for both singular
and plural.

SPHENOPSID:  Another name for
arthrophyte.

STEGOCERAS:  [stegg-AWE-sair-uss]
"Horny Roof."  Late Cretaceous, bone-
headed dinosaur.  Bipedal herbivore,
growing to 6 and a half feet in length.
Relative of Pachycephalosaurus.  Found
in western North America.  [Montana;
Alberta, Canada]

STEGOSAURIA:  This clade is made of
the roofed (sometimes called plated)
dinosaurs, and includes the stegosaurs
and huayangosaurs.  Together with the
ANKYLOSAURS [and SCELIDOSAURS]
they form the clade Thyreophora.

STEGOSAURUS:  [Stegg-oh-SOAR-uss]
"Roofed Reptile."  Plated dinosaur of the
Late Jurassic Period which grew up to
29 feet in length.  This is the only plated
dinosaur known to be in North America.
The 17 plates of bone aligned in two
rows along the back of Stegosaurus
probably were used in regulating body
temperature.  Four prominent spikes
were located at the end of a muscular
tail.  Found in western North America.
[Colorado; Wyoming; Utah]

STRUTHIOMIMUS:  [Strew-th-ee-oh-
MEEM-uss]  "Ostrich Mimic."  Late
Cretaceous, bipedal, theropod dinosaur
which grew up to 13 feet in length.
Found in Alberta, Canada.

STYRACOSAURUS:  [sty-Rack-oh-
SOAR-uss]  "Spiked Reptile."  Late
Cretaceous, short-frilled, ceratopian
dinosaur which grew up to 18 feet in
length.  The back edge of the frill
contained 6 long spikes, and the snout
had a long horn.  Two hollow window-
like openings in the frill, just like those
of Centrosaurus, probably were covered
with flesh in life.  Found in western
North America.  [Montana; Alberta,
Canada]

SUCCULENT:  A plant with thick, fleshy
stems or leaves that conserve moisture.
Juicy.

SUPERNOVA:  A really big star, with a
mass at least eight times that of the
sun, that blows up.  These are rare
celestial events, with only seven super
novae known to have occurred in our
Galaxy during recorded history.  A
super nova explosion throws material
from the star all over the Universe,
resulting in an extremely bright, short-
lived phenomenon that pours out vast
amounts of energy.

SUPERSAURUS:  [SUE-purr-Soar-uss]
"Super Reptile."  Late Jurassic,
sauropod dinosaur which grew to an
incredible length of up to 98 feet.
Quadrupedal, herbivorous dinosaur.
Closest relative of Diplodocus.  Found in
Colorado.

SYMMETRICAL:  Being of equal size and
shape on opposite sides of an axis.
TALONS:  Sharp claws of an animal.

TAPHONOMY:  The study of the burial
history of an organism.

TAXA:  Plural of taxon.

TAXON:  In biological classification, the
name given to a group of related
organisms of any rank, such as the name
given to a species, genus, family, order,
class, phylum, kingdom, or clade.

TAXONOMIC CATEGORY:  In biological
classification, the unit designation of a
group of related organisms of any rank,
such as species, genus, family, order,
class, phylum, kingdom, or clade.

TAXONOMY:  The theory and practice of
describing, classifying, and naming
organisms, living or fossil.

TENDON: A fiber of connective tissue
that forms the end of a muscle and
attaches it to a bone.

TERTIARY:  Tertiary Period:  A unit of
geologic time, which began about 5
million years ago and ended about 1.6
million years ago.  The Tertiary and
Quaternary periods together are the
Cenozoic Era.  During the Tertiary,
grasslands advanced at the expense of
forests, mammals reached their peak of
diversity, and spread to inhabit
virtually all land masses.  The earliest-
known fossils of Homo, our genus, are
found in rocks dating about 2 million
years old.

TETANURAE:  A related group (clade) of
dinosaurs which has two divisions: the
Carnosaurs and Coelurosaurs.  Included
in the Coelurosauria are the
Ornithomimosaurs (ostrich-like
dinosaurs), the Dromaeosaurs (bird-like
dinosaurs), and BIRDS.  Another way of
defining this group is THEROPODA
without the Ceratosauria.  The 4th and
5th fingers are lost.

TETHYS:  A great east-west trending
seaway that lay between Laurasia and
Gondwana during the Paleozoic and
Mesozoic eras.  The final closure of this
circum-equatorial ocean began with the
docking of India against Asia in the
Eocene Epoch, about 50 million years
ago, followed in the Miocene by Africa's
collision with southern Europe.  The Alps
and Himalayas arose from the vise-like
squeezing of Tethys between Laurasia
and Gondwana.

TETRAPOD:  "Four-legged."  A four-
legged or four-limbed vertebrate that
may use all legs for walking
(quadruped), but may also be bipedal.
Included are:  Amphibians, Sauropsids
(Reptiles plus Birds) and Synapsids
("Pelycosaurs" plus Therapsids and
Mammals).

THECODONT:  (THEE-koe-dont)  "Socket
Tooth."  A mixed group of early
archosaurs from the Permian and
Triassic periods that includes ancestors
of dinosaurs, crocodiles, and
pterosaurs.

THEROPOD:  Bipedal, flesh-eating
saurischian dinosaurs.

THYREOPHORA.  This group of dinosaurs
consists of the closely related
Scelidosauridae, Stegosauria, and
Ankylosauria.

TIBIA:  The larger of the two bones of
the hind leg below the knee.  The shin
bone.

TON:  A unit of weight equal to 2,000
pounds (short ton), commonly used in
the United States and Canada.  In Great
Britain, the long ton of 2240 pounds is
used.  A metric ton is 1000 kilograms,
or 2204.6 pounds, and is sometimes
spelled tonne.

TOOTH BATTERY:  A complex unit
formed by interlocking teeth in multiple
rows, as many as 5 or 6.  The best
example is the tooth battery of
hadrosaurs, with over 600 teeth per
battery that are ever-growing, self-
sharpening, and always being replaced
from below.

TORSO:  The trunk of the body.  That
part of the body excluding the head,
pelvis, and limbs.

"TRACHODON:"  [TRACK-oh-donn]
"Rough Tooth."  Late Cretaceous, duck-
billed dinosaur.  An old name no longer in
use.  See Edmontosaurus.

TRIASSIC:  Triassic Period:  A unit of
geologic time, the first period in the
Mesozoic Era.  The Triassic lasted from
about 251 million to 208 million year
ago.  Fossils of both dinosaurs and
mammals first appeared in the Carnian
Stage of the Upper Triassic.

TRICERATOPS:  [try-SAIR-ah-tops]
"Three-horned Face."  Late Cretaceous,
ceratopian dinosaur which grew up to
about 30 feet in length.  A quadrupedal
herbivore, Triceratops was one of the
largest and heaviest of all ceratopians.
Triceratops had two long brow horns, a
short nose horn, and a long frill made of
solid bone.  The last-known dinosaur to
become extinct.  Found in western North
America [Colorado; Montana; South
Dakota; Wyoming; Alberta, Canada; and
Saskatchewan, Canada].

TRIPOD:  Having three feet or legs.
Tripodal is to have a three-legged
stance.

TUOJIANGOSAURUS:  [too-Hwang-oh-
SOAR-uss]  "Reptile from Tuojiang."
Late Jurassic, plated dinosaur
possessing tail spikes and back plates
made of bone, both of which were
smaller than those on Stegosaurus.
Quadrupedal herbivore up to 20 feet in
length.  Found in People's Republic of
China.

TYPE SPECIMEN:  An actual specimen
used to describe a new species, and thus
is part of the basis for defining it.

TYRANNOSAURUS:  [tye-Rann-oh-
SOAR-uss]  "Tyrant Reptile."  The
largest flesh-eating land animal ever
known on Earth.  Late Cretaceous
theropod.  Bipedal, flesh-eating dinosaur
that grew up to 50 feet long.  Its skull
was over five feet in length, with jaws
more than 4 feet long, and teeth up to 8
inches from root to tip.  The front limbs
were extremely small for the size of the
body, about as long as a person's arm,
yet extremely strong.  The arm of
Tyrannosaurus ended in a two-fingered
hand, each finger bearing a stout claw.
Found in western North America
[Colorado; Montana; New Mexico, South
Dakota; Texas; Utah; Wyoming; Alberta,
Canada; and Saskatchewan, Canada],
Peoples's Republic of China, and
Mongolian Peoples's Republic.
UBIQUITOUS:  Being, or seeming to be
everywhere at the same time.

ULNA:  One of the two long bones of the
lower part of the front leg, or arm.  It
articulates with the radius, and is on the
same side of the leg as the fifth digit.
Most of the muscles that pull the arm
forwards and backwards attach to the
ulna.  The upper end of the ulna is the
"elbow."

ULTRASAURUS:  [Ull-trah-SOAR-uss]
"Ultra Reptile."  A name given to two
different dinosaurs that lived in
different places at different times and
may or may not be closely related.  One
is from South Korea and formally
named, the other is from western North
America [Colorado].  The skeletal
material recovered so far suggests they
both are probably Brachiosaurus.

UTAHRAPTOR:  [You-taw-RAPP-torr]
"Utah Predator."  Late Jurassic, large,
bipedal, flesh-eating dinosaur with a
sickle claw on each foot.  Large relative
of Deinonychus.  Known only from
fragments.  Found in North America.
[Utah]
VEGETATION:  The plants of an area or
region.

VELOCIRAPTOR:  [Veh-loss-ih-RAPP-
torr]  "Speedy Predator."  Late
Cretaceous, bipedal, flesh-eating
dinosaur with a sickle claw on each foot.
Relative of Deinonychus which grew up
to 11 feet in length.  Found in People's
Republic of China and Mongolian People's
Republic.

VENTRAL:  "Belly."  The underside of an
animal.  Opposite of dorsal.

VERTEBRA:  One of the segmented bones
of the spinal column, or backbone.  They
begin at the base of the skull, to which
the first vertebra is joined, and then
pass over the hips at the pelvis.
Vertebrae beyond the pelvis are
referred to as caudals, or tailbones.
Plural is vertebrae.
"WARM-BLOODED:"  An outdated term
once used for living birds and mammals,
animals that maintain a nearly uniform
body temperature, generally higher than
their surroundings.

WOOLLY MAMMOTH:  A hairy elephant
with large tusks that lived during the
latest ice age and became extinct
approximately 4,000 years ago.