Glossary SCO - SIC
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Scorpion
Scorpions are arachnids, the group that includes spiders and horseshoe
crabs. Typical features include an elongated body, pincers and a curved
segmented tail with a venomous tip. The earliest scorpions appeared on
land in the Silurian period,some 430 million years ago.
Scrubland
A landscape that is dominated by scattered drought-tolerant shrubs. A
shrub is a woody plant less than five metres high.
SCUTE
(pronounced skoot) A scute is a bony plate embedded in the skin. It serves
as armor for an animal. Scutes may have been covered by a layer of horn.
SCUTELLOSAURUS
(pronounced skoo-TELL-oh-SAWR-us) Scutellosaurus (meaning: "little
shield lizard") was an early, primitive dinosaur. It was about 4
feet (1.2 m) long and weighed about 22 pounds (10 kg). It had a long tail,
a long body and hundreds of bony plates (of six different varieties) that
acted as armor. Its thin hind legs were much longer than the front legs.
It was a semi-bipedal animal: it could walk on two or four legs. It was
an ornithischian dinosaur. This plant-eater lived during the late Jurassic
Period, about 208 million-200 million years ago. Fossils (two incomplete
skeletons and hundreds of bony armor plates) have been found in Arizona,
USA. Scutellosaurus was named by Edwin Colbert in 1981. The type species
is S. lawleri.
SCYTHIAN EPOCH
(pronounced SY-thee-en EP-ock) The Scythian epoch was the early (lower)
part of the Triassic Period, about 248 million to 242 million years ago,
the beginning of the Mesozoic Era.
Seaweed
Large algae that grows in the sea or in the tidal reaches of the sea.
SECERNOSAURUS
(pronounced see-SIR-no-SAWR-us) Secernosaurus (meaning: "separated
lizard") was a small duck-billed dinosaur, a hadrosaur, from the
late Cretaceous period, about 73-65 million years ago. It was about 10
ft (3 m) long. It isn't known whether or not it had a crest. The type
species is S. koerneri. Fossils (only a few pelvic bones and a partial
skull) were found in Argentina, South America. Secernosaurus is the first
duck-bill found in South America (most duck-bills and their ancestors,
the iguanodonts, have been found in North America). Secernosaurus was
named by Brett-Surman in 1979.
SEDIMENT
Sediment is any material deposited by wind or water, like rocks and sand.
SEDIMENTARY ROCK
Sedimentary rock is rock that has formed from sediment. Most fossils are
found in exposed sedimentary rock. In a sequence of sedimentary rocks,
the lowest layers are the oldest and the uppermost layers are the youngest
(this is the Law of Superposition).
Seed fern
Seedferns were an important group of plants that evolved during the Carboniferous
period. They possessed fern-like foliage but differed from the true ferns
because they were seed-bearing plants, or gymnosperms. This meant they
were not dependent on the presence of water for reproduction like the
true ferns, that are pteridophytes. Seed ferns were common in the Triassic
and Jurassic periods, but became extinct in the Early Cretaceous period.
SEELEY, HARRY G.
Harry Govier Seeley (1839-1909) was a British paleontologist. In 1887,
he divided the dinosaurs by hip structure, into the orders Saurischia
and Ornithischia. He named Agrosaurus (1891), Anoplosaurus (1878), Aristosuchus
(1887), Craterosaurus (1874), Macrurosaurus (1876), Orthomerus (1883),
Priodontognathus (1875), Rhadionsaurus (1881), and Thecospondylus (1882).
SEGISAURUS
(pronounced SEG-ee-SAWR-us) Segisaurus (meaning: "Segi canyon lizard")
was a goose-sized, bipedal, fast-moving, meat- and insect-eating dinosaur
from the early Jurassic Period, about 206 million to 200 million years
ago. Its fossils have been found in Arizona. It was a lightly-built, bird-like
theropod dinosaur with a long flexible neck, long head, three-toed feet,
a short body, long tail, long, strong legs, arms with long forearms and
long, clawed hands. Its collar bone was similar to that of a bird (this
characteristic is unusual for dinosaurs and indicated a close link to
birds). Segisaurus was named by Charles L. Camp in 1936.
SEGNOSAURUS
(pronounced SEG-noh-SAWR-us) Segnosaurus (meaning: "slow lizard")
was a meat-eating dinosaur perhaps 13 to 30 feet (4-9 m) long (its size
is uncertain). It lived during the late Cretaceous Period, roughly 97.5
million to 88.5 million years ago. It was a theropod from what is now
Mongolia. This biped is known from 3 partial skeletons. It was named by
Perle in 1979 . The type species is S. galbinensis.
SEISMOSAURUS
(pronounced SIZE-moh-SAWR-us) Seismosaurus (meaning: "Earthquake
Lizard") was a huge diplodocid dinosaur, up to 170 feet (52 m) long.
It may be the longest dinosaur. It lived during the late Jurassic Period,
about 156 million-145 million years ago. It had a long neck, whip-like
tail, and gizzard stones to aid digestion in its stomach. Fossils have
been found in New Mexico, USA. The type species is S. halli.
SELLOSAURUS
(pronounced SELL-oh-SAWR-us) Sellosaurus (meaning: "saddle lizard")
was a sauropodomorpha, a primitive plant-eater from the late Triassic
Period, from 219 -208 million years ago. It was about 21 ft (6.5 m) long.
Sellosaurus was named in 1908 by paleontologist von Huene. 21 Partial
skeletons, together with gastroliths, were found in Germany. The type
species is S. gracilis.
SENONIAN EPOCH
(pronounced cen-NOH-nee-an EP-ock) The Senonion epoch was the late (upper)
part of the Cretaceous Period, about 89 million to 65 million years ago,
the end of the Mesozoic Era. The Senonian was named by the French paleontologist
Alcide Dessalines d'Orbigny in 1842.
SERENO, PAUL C.
Paul C. Sereno (1958 - ) is a US paleontologist from the University of
Chicago who has worked in South America, Asia and Africa. He excavated
a giant Carcharodontosaurus (1996), found and named Afrovenator (with
others, 1994), named the oldest-known dinosaur, Eoraptor (with others,
1993), Suchomimus (1998), Jobaria, and Nigersaurus. Sereno named: Deltadromeus
(1996) and Marasuchus (with Arcucci, 1994). He has rearranged the dinosaur
family tree, reorganizing the ornithischians and naming the group Cerapoda
(1986), formed from the ornithopods and marginocephalians.
SERRATED
Serrated means having a jagged edge that is good for sawing. Serrated
teeth are good for cutting through meat.
SEXUAL DIMORPHISM
Sexual dimorphism is characteristic of having two different forms, one
for the males and another for the females of a species. It is very difficult
to determine which fossils were male and which were female.
SEYMOURIA
(pronounced see-MORE-ee-ah) Seymouria (named after Seymour, Texas, where
it was found) was an amphibian from the early Permian period. It was about
2 feet (60 cm) long. It had a strong backbone, four short, sturdy legs,
and a short tail, Unlike other amphibians, Seymouria had relatively shorter
jaws, ears marked by a notch, and the skull had fewer bones. Its long
bones feet and digits were almost like that of a reptile. Seymouria laid
its eggs in water. When they hatched, the young changed into their adult
shapes (like modern-day frogs change from tadpoles to adults). Fossils
have been found in North America.
Shale
A fine-grained sedimentary rock produced by the consolidation of clay
materials which splits easily into distinct layers.
SHAMOSAURUS
(pronounced SHAM-oh-SAWR-us) Shamosaurus (meaning: "desert lizard")
was an armored, plant-eating dinosaur (an Ankylosaurid ankylosaur) from
the early Cretaceous Period. Shamosaurus was roughly 23 ft (7 m) long.
Three partial fossils were found in the Gobi desert in Mongolia. The type
species is S. scutatus. It was named by paleontologist Tumanova in 1983.
SHANSHANOSAURUS
(pronounced SHAHN-SHAHN-oh-SAWR-us) Shanshanosaurus (meaning: "Shanshan
(China) lizard") was a meat-eating dinosaur (an advanced theropod
and perhaps a tyrannosaurid) from the late Cretaceous Period. This predator
was roughly 6.5-10 ft (2-3 m) long. A partial fossil was found in NW China.
The type species is S. huoyanshanensis. It was named by paleontologist
Dong in 1977.
SHANTUNGOSAURUS
(pronounced SHAHN-DUNG-oh-SAWR-us) Shantungosaurus (meaning: "Shandong
lizard") is the largest-known duck-billed dinosaur (a hadrosaur)
from the late Cretaceous Period, about 83 to 73 million years ago. This
beaked plant-eater was about 38-48 ft (12-15 m) long. It had a wide, flat
head and is very similar to Edmontosaurus. They type species is S. giganteus.
5 incomplete skeletons were found in China. It was named by paleontologist
Hu in 1973.
SHANXIA
(pronounced shahn-SHEEH-ah) Shanxia (named after Shanxi Province, China)
was an armored, plant-eating dinosaur about 11.5 ft (3.5 m) long. This
ankylosaur dates from the late Cretaceous Period. The type species is
S. tianzhenensis. A partial skeleton was found in China. Shanxia was named
by Barrett, You, Upchurch, and Burton in 1998.
SHAROVIPTERYX
(pronounced shahr-ov-IP-ter-iks) Sharovipteryx (meaning: "Sharov's
wings"), aka Podopteryx, was a Pterosauromorpha (a gliding thecodont,
a pre-pterosaur) from the early Triassic Period, about 245 million years
ago. Sharovipteryx was a gliding animal that used its uropatagium, a small,
fibrous flap of skin that stretched from the very long legs and the tail.
It had large eyes, a long snout, and small triangular teeth. A single
fossil (together with some skin impressions) was found in Madygen, Kirghizia,
Asia. Sharovipteryx was named by Cowen in 1981 (to honor the paleontologist
Alexander Sharov, who found the fossil in 1971, and originally called
it Podopteryx). The type species is S. mirabilis.
Shield bug
This small insect gets its name because the female sits over, or shields,
her hatching eggs and young.
SHIVA CRATER
The Shiva crater is a huge impact crater located under the Arabian Sea
off the coast of India near Bombay. This crater dates from the K-T boundary,
65 million years ago, when the Chicxulub crater at the tip of the Yucatán
Peninsula also formed. Although it has shifted because of sea floor spreading,
when pieced together it would be about 370 miles (600 km) by 280 miles
(450 km) across and 7.5 miles (12 km) deep (and may be just part of a
larger crater). It is estimated to have been made by a bolide (an asteroid
or meteoroid) 25 miles (40 km) in diameter. This crater was named by the
paleontologist Sankar Chatterjee for Shiva, the Hindu god of destruction
and renewal.
SHOCKED QUARTZ
Shocked quartz is quartz that has undergone deformation due to extreme
pressure and heat. It has been found in the layer that marks the K-T boundary,
lending credence to the Alvarez impact theory.
SHONISAURUS
Shonisaurus was an Ichthyosaur about 49 feet (15 m) long. It had a huge,
whale-like body, four fin-like flippers, a dorsal fin, a fish-like tail,
and teeth (only in the front of the jaws). It lived during the late Triassic
Period in what is now North America. It was not a dinosaur, but another
type of extinct reptile that lived during the time of the dinosaurs.
Shrimp
Shrimps are crustaceans, related to crabs and lobsters. They have semi-transparent
bodies which are flat and flexible in the middle with a fan-like tail.
SHUNOSAURUS
(pronounced SHOO-noh-SAWR-us) Shunosaurus (meaning: "Sechuan lizard;"
Sechuan is a province in China) was a sauropod dinosaur about 40 feet
(11 m) long. It is the only sauropod known that had a bony club at the
end of its tail, formed by enlarged vertebrae. This small tail club had
two small spines on it and was probably used for defense. It was a quadrupedal
plant eater with a long tail, a long neck, a small head, a massive body
and relatively short legs. It lived during the mid-Jurassic Period, about
175 million to 163 million years ago. Fossils include 20 skeletons (with
5 skulls) found in China. It was named by Chinese paleontologists Dong,
Zhou and Zhang in 1983.
SHUVOSAURUS
(pronounced SHOE-voh-SAWR-us) Shuvosaurus (meaning: "Shuvo's lizard;"
named for Shuvo, the discoverer of the fossil and the son of Chatterjee)
was a 10 ft (3 m) long bipedal reptile from the late Triassic Period.
At first, this reptile was thought to be an ornithomimid dinosuar, but
is now thought to be a rauisuchian thecodont. Shuvosaurus was named by
paleontologist Sankar Chatterjee in 1993. Only the fossilized toothless
skull was found in the Dockum Formation, Texas, USA. The type species
is S. inexpectatus.
SHUVUUIA
Shuvuuia (from the Mongolian word for bird) was a 10 ft (3 m) long bird-like
dinosaur that lived during the late Cretaceous Period. It was a fast-running,
bird-like, chicken-sized dinosaur. Shuvuuia had a pointed beak (that could
open very wide), tiny teeth, long legs, short arms, a long tail, and only
one functional finger (clawed, of course) on each hand. Shuvuuia was named
by paleontologists Chiappe, Norell and Clark in 1998. Two skulls and some
bones have been found in the Gobi Desert, Asia. The type species is S.
deserti.
SIAMOSAURUS
(pronounced si-AM-oh-SAWR-us) Siamosaurus (meaning: "Siamese lizard")
was a large, sail-backed, early spinosaurid theropod from the early Cretaceous
Period. This meat-eating biped was named by paleontologists Buffetaut
and Ingavat in 1986 and found in Thailand. The type species is S. suteethorni.
SIAMOTYRANNUS
(pronounced sie-AM-oh-ti-RAN-us) Siamotyrannus (meaning: "Siamese
tyrant") was a tyrannosaurid theropod from the early Cretaceous Period.
Fossils were found in northeast Thailand. This meat-eating biped was named
by paleontologists Buffetaut, Suteethorn, and Tong in 1996.
SICKLE-LIKE CLAW
Some theropod dinosaurs, including the dromaeosaurids (eg., Velociraptor,
Utahraptor, and Deinonychus) and Megaraptor were armed with a sickle-like
claw on each hind foot, making them deadly predators. These sharp claws,
varying in length from a few inches to over 14 inches (35 m), could eviscerate
prey easily. When alive, this claw would have been sheathed in a horny,
keratinous material much like our fingernails, making the claw even bigger,
longer and sharper.