Leurospondylus
Encyclopedia
Leurospondylus is a genus
of plesiosaur
whose family
is not known for certain, but is thought to be Plesiosauridae
.
words, leuros (λευρός) meaning "even", "flat" or "smooth", and spondylos (σπόνδυλος) meaning "vertebra." The name of the type species
L. ultimus comes from the Latin
ultimus meaning "last." It was so named because this genus was the latest known occurrence of a fossil
plesiosaur when it was described in 1913."
noted that the vertebrae are short and similar to those of pliosaurs, while the scapula
e and coracoids bear resemblance to those of elasmosaurids
, thus making it difficult to determine to which family
it belongs. There is some speculation that the Leurospondylus specimen is either a juvenile of a known species, or in its own, unrecognized taxonomic
group.
. This area is part of the Horseshoe Canyon Formation
in Alberta
, Canada
. The occurrence of this juvenile fossil in an identifiably brackish environment led to the conclusion that plesiosaurs spent their early lives in rivers and estuaries
. However, some plesiosaurs spent their adult lives in fresh water also; whether Leurospondylus grew up and then left, or grew up and stayed in a fresh water ecosystem
has not been determined.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of plesiosaur
Plesiosaur
Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...
whose family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
is not known for certain, but is thought to be Plesiosauridae
Plesiosauridae
Plesiosauridae was a monophyletic family of plesiosaurs.-References:...
.
Etymology
The name Leurospondylus comes from a fusion of two GreekGreek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
words, leuros (λευρός) meaning "even", "flat" or "smooth", and spondylos (σπόνδυλος) meaning "vertebra." The name of the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
L. ultimus comes from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
ultimus meaning "last." It was so named because this genus was the latest known occurrence of a fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
plesiosaur when it was described in 1913."
Description
The first described Leurospondylus was a juvenile. It was found with 12 vertebrae but is thought to have had twice that number, and was estimated to be roughly seven feet long as a juvenile. Samuel Paul WellesSamuel Paul Welles
Samuel Paul Welles was an American palaeontologist, who was Research Associate at the Museum of Palaeontology, University of California, Berkeley. He took part in excavations at the 'Placerias Quarry' in 1930 and the Shonisaurus discoveries of 1954 and later, in what is now the Berlin-Ichthyosaur...
noted that the vertebrae are short and similar to those of pliosaurs, while the scapula
Scapula
In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
e and coracoids bear resemblance to those of elasmosaurids
Elasmosauridae
Elasmosauridae was the family of plesiosaurs. They had the longest necks of the plesiosaurs and survived from the Late Triassic to the end of the Cretaceous. They had a diet of fish and shelless cephalopods.-Size:...
, thus making it difficult to determine to which family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
it belongs. There is some speculation that the Leurospondylus specimen is either a juvenile of a known species, or in its own, unrecognized taxonomic
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
group.
Distribution
The first Leurospondylus was found in the brackish paleoenvironment represented by the Edmonton beds located on the present-day Red Deer RiverRed Deer River
The Red Deer River is a river in Alberta, Canada. It is a major tributary of the South Saskatchewan River.Red Deer River has a total length of and a drainage area of...
. This area is part of the Horseshoe Canyon Formation
Horseshoe Canyon Formation
The Horseshoe Canyon Formation is part of the Edmonton Group and is up to 230m in thickness. It is Late Campanian to Early Maastrichtian in age and is composed of mudstone, sandstone, and carbonaceous shales...
in Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. The occurrence of this juvenile fossil in an identifiably brackish environment led to the conclusion that plesiosaurs spent their early lives in rivers and estuaries
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
. However, some plesiosaurs spent their adult lives in fresh water also; whether Leurospondylus grew up and then left, or grew up and stayed in a fresh water ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
has not been determined.
External links
- http://www.plesiosaur.com/database/pdf/brown1913Leurospondylus.pdf
- http://www.ppne.co.uk/index.php?m=show&id=12527