Glossary L
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LINNEAN SYSTEM
The Linnean System is a method of classifying organisms based on a simple
hierarchical structure. Organisms are divided into groups using the following
system: Kingdom, Phylum, Class, Order, Family, Genus and Species.
Liopleurodon
The largest of carnivores, this gigantic, marine reptile lived in the
Late Jurassic period. It inhabited the wide open sea, and had four paddle
like limbs to propel it. It had a keen sense of smell and a ferocious
dental array. It grew up to approximately 25 metres long and weighed up
to 150 tonnes.
LIVING FOSSILS
A living fossil (an oxymoron) is an organism that lived during ancient
times and still lives today, relatively unchanged, like the Coelacanth,
the horseshoe crab, the gingko tree, cycads, horsetails, club mosses,
and many, many other well-adapted organisms.
Lizard
Lizards are cold-blooded reptiles that are similar to their primitive
reptile ancestors that emerged in the Triassic period. Most are egg-laying
although some have developed the ability to give birth to live young.
Lizard-hipped
Lizard-hipped dinosaurs, or Saurischia, are one of the two main sub-divisions
of the dinosaurs. The lizard-hipped dinosaurs were split into the carnivorous
theropods and the herbivore sauropodomorphs (sauropods and prosauropods).
Evolved in the Triassic period, the group died out with the mass extinction
at the end of the Cretaceous period. The name derives from the distinctive
arrangement of the pelvis.
LOBE-FINNED FISH
Lobe-finned fish (Crossopterygii) are bony fish whose fins are supported
on fleshy lobes. Lobe-finned fish appeared during the Silurian period
(roughly 420 million years ago). The Coelacanth and the extinct Rhipidistians
are examples of lobe-finned fish.
LONGISQUAMA
Longisquama was a small, early archosaur (not a dinosaur) that lived during
the early Triassic Period, about 245 million years ago. This unusual reptile
was about 6 inches long, had a long tail, a pointed snout, and long feather-like
scales coming out of its back (possibly arranged in pairs). These scales
may have been used for gliding from trees. Fossils have been found in
Kyrgyzstan. Longisquama was named by Alexander Sharov in 1970. The type
species is L. insignis.
LONG NECK
The long-necked dinosaurs were sauropods like Diplodocus, Apatosaurus,
and Brachiosaurus.
LOPHORHORTHON
(pronounced "LOF-or-HOH-thon") Lophorhothon (meaning: "crested
snout") was a duck-billed dinosaur that lived during the late Cretaceous
Period, about 83-73 million years ago. This plant-eater was about 15 ft
(4.5 m) long; it had a deep skull, with wide eye holes. It had a short
snout with a small, pyramid-shaped crest located above the nose. Fossils
have been found in Alabama, North Carolina, and perhas Mississippi, USA.
Lophorhothon was named by Langston in 1960. The type species is L. atopus.
LOSILLASAURUS
Losillasaurus was a huge, plant-eating dinosaur with a long neck, long,
whip-like tail, small head, and bulky body. This diplodocid sauropod lived
during the late Jurassic to early Cretaceous periods, roughly 145 million
years ago. Incomplete fossils were found in the Collano Rock Formation,
Spain. The type species is L. giganteus; it was named by paleontologists
M.L. Casanovas, J.V. Santafe and J.L. Sanz in 2001.
LOURINHANOSAURUS
(pronounced loh-reen-YAH-noh-SAWR-us) Lourinhanosaurus (meaning: "Lourinhã
Formation [a rock formation in west-central Portugal] lizard") was
a bipedal, meat-eating dinosaur that lived during the late Jurassic Period
(roughly145 million years ago). It was about 14.8 feet (4.5 m) long. This
allosaurid carnosaur had longer vertebrae that other allosaurids; it lived
in what is now Portugal. The type species is L. antunesi; Lourinhanosaurus
was named by Octávio Mateus in 1998. This dinosaur is known from
a partial skeleton, 32 gastroliths (stones that were swallowed to help
digestion) in the rib cage, and some fossilized eggs.
LOURINHASAURUS
(pronounced loh-reen-yah-SAWR-us) Lourinhasaurus (meaning: "Lourinhã
Formation [a rock formation in west-central Portugal] lizard") was
a quadrupedal, plant-eating dinosaur that lived during the late Jurassic
Period (roughly145 million years ago). It was about 57 feet (17 m) long.
This sauropod it lived in what is now Portugal. The type species is L.
alenquerensis (it was found in described in 1957 by de Lapparent and Zbyszewski,
who originally thought it was Apatosaurus); Lourinhasaurus was named by
Dantas, Sanz, Da Silva, Ortega, Dos Santos and Cachao in 1998. This dinosaur
is known from three partial skeletons and about 100 gastroliths.
LOW SEASONALITY
Low seasonality is when there is only a small difference in temperature
between the seasons (with mild winters and summers). Compare to stong
seasonality, in which the difference in temperatures between the seasons
is big (for example, with a hot summer and a cold winter).
LUFENGOSAURUS
(pronounced LOO-FUHNG-oh-SAWR-us) Lufengosaurus (meaning: "Lufeng
(China) lizard") was a plateosaurid prosauropod, a long-necked, small-headed,
quadrupedal, herbivore dinosaur with widely spaced teeth. It was about
20 feet (6 m) long. This large plant-eater lived in what is now China
during the early Jurassic Period (208-200 million years ago). Lufengosaurus
was named by Chung Chien Young in 1941.
LULL, R. S.
Richard Swann Lull (1867-1957) was a vertebrate paleontologist who headed
Yale's Peabody Museum (1922-1936) . Lull said that the best fossils collecting
could be done in the basement of the Peabody Museum. He named the following:
Anatosaurus Lull and Wright, 1942 (an obsolete name for Edmontosaurus),
Anchisauripus (an ichnogenus of theropod dinosaur) in 1904, Diceratops
Hatcher vide Lull, 1905, Proceratops Lull, 1906.
Lungfish
This group evolved in the Devonian period and has relatives that still
exist today. They use their swim-bladder as a lung to survive when rivers
dry up during droughts by burrowing into the substrate and wrapping themselves
in a waterproof cocoon.
LYCAENOPS
Lycaenops (meaning: "wolf face") was a small therapsid, a reptilian
ancestor of the mammals. It was about 3.25 feet (1 m) long, walked on
4 long legs and had a pointed tail. It was about 16 feet (5 m) long. This
meat-eater may have hunted in packs, preying upon plant-eaters like Moschops.
It had long, deep-ropoted canine teeth (fangs); its skull was deeper in
front to hold these large teeth. It lived during the late Permian period,
before the dinosaurs evolved. Fossils have been found in South Africa
and European Russia. Classification: Subclass Synapsida, Order Therapsida
(advanced synapsids and the direct ancestors of mammals).
LYCOPSIDS
Lycopsids (club mosses) are primitive, vascular plants (pteridophytes)
that evolved over 375 million years ago (during the Devonian). Huge club
mosses went extinct during the Permian mass extinction; smaller ones lived
during the time of the dinosaurs. These plants live near moisture (in
order for their spores to germinate). These fast-growing, resilient plants
propagate with rhizomes (underground stems).
LYCORHINUS
Lycorhinus (meaning: "wolf snout") was a heterodontosaurid dinosaur
known only from a lower jaw bone with very long and sharp canine teeth.
It was a small, bipedal, herbivore dinosaur from South Africa during the
early Jurassic Period (208-200 million years ago). It was named by S.
H. Haughton in 1924.
LYSTROSAURUS
Lystrosaurus (menaing "shovel lizard") was a heavily-built,
early Triassic Period quadruped (a dicynodont, a mammal-like reptile)
with a short, stubby tail. Instead of teeth it had two tusk-like fangs
made of horn. It was a plant-eater about 3 feet (1 m) long and about 200
pounds. It lived in herds near lakes and swamps. Since fossils of Lystrosaurus
had been found in South Africa, India, Europe, and Asia, finding Lystrosaurus
fossils in Antarctica was further evidence that during the late Permian
period and Triassic Period, the continents were connected into one large
continent (called Gondwananland). They may have been hunted by Chasmatosaurus,
a carnivorous thecodont.