Glossary EUP - EXT
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EUPARKERIA
Euparkeria was a small, early, land-dwelling archosauriform (a reptile
closely related to the archosaurs; Euparkeria was a branch off the evolutionary
tree very soon before the emergence of dinosaurs). This fast-running quadruped
had a semi-erect posture; it could walk on four legs, the front limbs
were much shorter than the hind limbs, indicating that it may have been
able to run bipedally for short distances. This carnivore (meat-eater)
had a long tail, four-fingered hands, large, flexible jaws and many sharp,
serrated teeth in sockets. It was about 1.5 ft (0.5 m) long. Euparkeria
dates from the early Triassic Period, about 225 million years ago. Fossils
have only been found in southern Africa.
EUPATAGUS
Eupatagus antillarum is an extinct type of sand dollar about 4-5 inches
(12 cm) in diameter. It dates from the Eocene epoch, (about 58-37 million
years ago). Many of these fossils have been found in Florida, USA. (Phylum
Echinodermata, Class Echinoidea)
EURAMERICA
Euramerica was the joined continents of Europe and the Americas (during
parts of the Mesozoic Era).
EURASIA
Eurasia is the combined, joined land masses of Europe and Asia.
EURHINOSAURUS
Eurhinosaurus was an Ichthyosaur about 6.5 feet (2 m) long). Unlike other
Ichthyosaurs, it had an elongated upper jaw, perhaps used for obtaining
food by poking into the sea bed. From what is now Germany during the early
Jurassic Period. It was not a dinosaur, but another type of extinct reptile.
EURONYCHODON
(pronounced your-on-IK-oh-don) Euronychodon (meaning: "Europoean
claw-tooth") was a Tetanuran theropod related to Deinonychus. This
bipedal meat-eater was perhaps 6.5 ft (2 m) long.z It lived during the
late Cretaceous Period. This dinosaur is only known from fossil teeth
found in Portugal. The type species is E. portucalensis. Euronychodon
was named by paleontologists Telles Antunes and Sigogneau-Russell in 1991.
EURYAPSID
Euryapsids were a group of marine reptiles (now extinct) that had a single
skull opening behind the eye socket, a subgroup of the diapsids. Euryapsids
include plesiosaurs, nothosaurs, placodonts, and ichthyosaurs.
EURYPTERIDA
Eurypterida (meaning: "wide wing") are extinct carnivorous marine
arthropods (segmented invertebrates with a chitinous exoskeleton and jointed
legs), also called "sea scorpions." These hunters had a scorpion-like
stinger which may have contained poison, 3 pairs of jointed legs, 2 clawed
arms, and strong jaws. Some had two paddles for swimming. They may have
swum on their backs. Eurypterids include Eurypterus, Onychopterella, Pterygotus,
Mixopterus, Slimonia, Palmichnium (an ichnogenus, i.e., known from fossilized
trackways), etc. Eurypterids date from the early Paleozoic Era, arising
during the Ordovician period, over 400 million years ago. Many are found
from the Silurian period. They went extinct in the Permian mass extinction.
Eurypterids are the state fossil of New York.
EUSKELOSAURUS
(pronounced YOO-skel-oh-SAWR-us) Euskelosaurus (meaning: "good-limbed
lizard") was a plant-eating dinosaur named for its 3 ft (1 m) long
thigh bone. This enormous browser was about 30-40 ft (9-12 m) long and
may have weighed about 1.8 tonnes. A plateosaurid prosauropod, it lived
during the late Triassic Period in what is now Lesotho, South Africa and
Zimbabwe. Hundreds of fossilized bones have been found. Euskelosaurus
was named by Thomas Huxley in 1866. The type species is E. browni.
EUSMILUS
(pronounced you-SMILE-us) Eusmilus was a saber-toothed cat that lived
during the late Eocene (about 40 million years ago) in Eurasia, and spread
eastward over the Bering land bridge to North America by the Oligocene
Epoch. Fossils have been found in France and the USA (in North Dakota,
South Dakota, and Wyoming). This predator had long, saber-like upper canine
teeth, but only 26 teeth in its mouth (most carnivores have about 44 teeth).
Its huge jaws could open about 90 degrees, allowing it to stab its victims
with its incisors. Eusmilus was about 8 feet (2.5 m) long; it had a long,
low body and a long tail. Classification: Superfamily Feloidea (cats,
mongooses), Family Felidae, Subfamily Machairodontinae, Genus Eusmilus,
species cerebralis, etc.
EUSTHENOPTERON
(pronounced you-sthen-OP-ter-on) Eusthenopteron was a large, fleshy-finned
bony fish that lived during the late Devonian (over 400 million years
ago). Eusthenopteron had characteristics of early tetrapods, and may have
been a forerunner of amphibians. Eusthenopteron had pyramidal bones in
its paired fins, a structure similar to that of the limb bones in later
land animals. Its skull, backbone sructure, and tooth enamel are also
very similar to those of land animals. Eusthenopteron was a carnivore
(meat-eater) that had a three-pronged tail, an armored head, and a long
body. Its paired dorsa (back)l fins and anal fins were set near the tail;
the two pectoral fins were near the head and gills. Fossils of this sarcopterygian
fish have been found in Europe (Scotland and Russia) and Canada (Quebec).
Classification: Class Osteichthyes (bony fish), Subclass Sarcopterygii
(fleshy-finned fish), Infraclass Rhipidistia, Order Psteolepiformes (rhipidistians),
Genus Eusthenopteron.
Eustreptospondylus
This medium-sized carnivore lived in the Late Jurassic period. Eustreptospondylus
may have been a scavenger that could swim from island to island when attracted
by the smell of meat, using its tail as a balance. It could grow up to
5 metres long, and weigh up to half a tonne.
EUTHECODON
Euthecodon is an extinct genus of crocodilian that lived during the Neogene
(the middle Miocene, roughly 13-16 million years ago). Fossils have been
found in Ombo, Kavirondo Gulf, Kenya, Africa. It was not a dinosaur.
Evolution
Evolution is a process in which the gene pool of a population gradually
(over millions of years) changes in response to environmental pressures,
natural selection, and genetic mutations. All forms of life came into
being by this process.
EVOLVE
To evolve is to develop by the process of evolution, changing in some
way as an adaptation to the environment.
EXOSKELETON
An exoskeleton is a tough, structural body armor made of chitin (a type
of protein). Arthropods (insects, arachnids, trilobites, crustaceans,
etc.) have exoskeletons.
EXTENSOR MUSCLE
An extensor muscle which straightens out a joint. (Compare with a flexor
muscle, its opposite)
EXTINCT
An animal species that is extinct has died out. Most animal species that
ever existed have gone extinct, including all the dinosaurs.
Extinction
Extinction is the process in which groups of organisms die out. The regular
dying-out of species and larger groups, and their replacement by more
advanced forms is the normal process of evolution. Sometimes however whole
orders of animals and plants have disappeared abruptly from the fossil
record in what are called mass extinctions.