Glossary GON - GYM
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Gondwanaland
The southern part of the super-continent known as Pangaea which stretched
from pole to pole during the Late Palaeozoic and Early Mesozoic Eras.
Gondwanaland comprised the continental masses of South America, Africa,
Arabia, Madagascar, India, Australia and Antarctica which were all joined
together into a single continuous land mass. The northern part of Pangaea,
called Laurasia comprised North America, Europe and Asia.
GONIATITIDA
Goniatitida are an order of extinct ammonoids (a type of mollusk). This
soft-bodied animal was protected by a single, spiral shell. It ate with
a file-like radula that had 7 "teeth," it had ten arms, and
it breathed through gills. The offspring were tiny, floating with currents
and being a component of plankton. Goniatitic mollusks lived from the
Devonian to Permian period. Goniatitida were named by paleontologist Hyatt
in 1884. Classification: Class Cephalopoda, Subclass Neocephalopoda, Infraclass
Ammonoidea, Order Goniatitida.
GORGONOPSID
Gorgonopsid (meaning: "Gorgon arch," Gorgon was a beast in Greek
mythology whose gaze could turn you to stone, and arch refers to synapsid
skull holes) was a synapsid, a mammal-like reptile that lived during the
Permian period, about 260 million years ago. They were the major predators
until they went extinct during the late Permian period, before the dinosaurs
evolved. They had large, powerful, square-shaped jaws with huge, sabre-like
canine and interlaced, socket-like teeth. Fossils have been found in South
Africa. The Gorgonopsidae are divided into 2 sub-families, the Rubidginae,
which had large, broad skulls, and the Gorgonopsinae, which comprised
most of the gorgonopsid genera.
GORGOSAURUS
(pronounced GORE-goh-SAWR-us) Gorgosaurus (meaning: "Gorgon lizard")
used to be thought to be an invalid name for Albertosaurus, but is now
believed to be a separate genus of tyrannosaurids. Gorgosaurus was named
by Paleontologist L. Lambe in 1914. It was a large, meat-eating dinosaur,
a theropod about 26-30 feet (8-9 m) long. This fierce predator had a large
head with many sharp teeth, tiny arms, large powerful legs, and a stiff
tail. Over 20 incomplete fossilized skeletons have been found in Alberta,
Canada and Montana, USA. This relatively intelligent dinosaur dates from
the late Cretaceous Period, roughly 76 to 68 million years ago. The type
species is G. libratus.
GOYOCEPHALE
(pronounced GOH-yoh-SEF-ah-lee ) Goyocephale (meaning: "elegant or
decorated head") was a thick-skulled, flat-headed, plant-eating dinosaur
with knobs and spikes on its pitted skull and large teeth. It dates from
the late Cretaceous Period, about 85 to 80 million years ago. This homalocephalid
pachycephalosaur was found in Mongolia (the skull and parts of the skeleton
were found). Goyocephale was named by Perle, Maryanska and Osmolska in
1982. The type species is G. lattimore.
GRADE
A grade (also called a paraphyletic group) consists of a common ancestor
and some, but not all, of its descendants. These are incomplete groups
based primarily on physical characteristics rather than directly on evolutionary
relationships. An example of a paraphyletic group is the dinosaurs (without
including the birds).
GRALLATOR
(pronounced GRAL-uh-tore) Grallator (meaning: 'stilt walker') was a herding
dinosaur known only from its fossilized footprints. It is an ichnogenus
The relatively common, three-toed tracks average about 7 inches (17 cm)
long. The shape and pattern of the bipedal prints (including the ratios
of the lengths of the toes) indicate that it was probably a small theropod
(a bipedal meat-eater) similar to Coelophysis. The tracks date from about
200 million years ago, during the very late Triassic Period to the early
Jurassic Period. Grallator trackways have been found in the USA (NJ, PA,
CT), Canada, and Europe.
GRAPTOLITE
Graptolites were a group of extinct marine colonial animals, most of which
lived attached to the sea bed. Graptolites lived from the Cambrian period
(roughly 540 to 505 million years ago) to the early to mid-Carboniferous
(360 to 320 million years ago). These small sea animals had a soft body,
tentacles, and a hard outer chitonous covering (similar to our fingernails);
they were bilaterally symmetrical. These widespread fossils are often
used as index fossils. Classification: Hemichordata (chordates lacking
a backbone)
GRAVIPORTAL
Graviportal means slow-moving due to massiveness.
GRAZER
A grazer is an animal that eats low-lying vegetation, such as grasses
and other low plants. Ankylosaurs were grazers.
GRAZING FOOD CHAIN
The grazing food chain is a model that describes the flow of organic energy
through organisms in an ecosystem. A trophic level is a level of this
grazing food chain. For example, plant-eaters are primary consumers; they
occupy the second trophic level in the grazing food chain.
GRENDELIUS
Grendelius was a lage Ichthyosaur, an extinct aquatic reptile. This carnivore
lived dring the late Jurassic period. Like all ichthyosaurs, they gave
birth to live young. They had a long, toothed snout and a fish-like tail
that moved like that of a modern-day fish. Fossils have been found in
the U.K.
GRESSLYOSAURUS
(pronounced GRES-lee-oh-SAWR-us) Gresslyosaurus was quadrupedal plant-eating
dinosaur that lived during the late Triassic Period. This 23 feet (7 m)
long dinosaur ate leaves high in the trees. Gresslyosaurus means "Gressly's
lizard," named to honor the Swiss geologist Amanz Gressly (1814-1865),
who coined the term" facies" to describe the aspects (or "faces")
of the terrain. Gresslyosaurus was named by Ruetimeyer in 1857 to replace
the preoccupied Dinosaurus. Gresslyosaurus is the same genus as Plateosaurus
robustus.
GRYPOSAURUS
(pronounced GRIP-oh-SAWR-us) Gryposaurus (meaning: "hook-nose lizard")
was a duck-billed dinosaur from the late Cretaceous Period, about 76 to
72 million years ago. This hadrosaurid was a plant-eater that was about
30 feet (9 m) long. It had a long, narrow skull, highly-arched nostrils,
and a big bump on its snout. Its skin had 0.25 inch (0.5 cm) wide polygonal
scales (shaped like polygons) on its neck, sides and belly. It had 0.5
inch (1.3 cm) wide cone-shaped plates on its tail, spaced about 2-3 inches
(5.2-6.8 cm) apart. It is known from a over 10 skulls, some bones, and
skin impressions found in Alberta, Canada. Gryposaurus was named by fossil
hunter L. Lambe in 1914. The type species is G. notabilis.
Gymnosperm
The gymnosperms are a large group of plants that include the seed ferns,
cycads, conifers and ginkgos. They evolved in the Devonian period and
possessed "naked seeds". This made them less reliant on water
for their reproductive cycle than the pteridophytes and gave them an advantage
in drier conditions.