Puijila
Encyclopedia
Puijila darwini is an extinct species
of pinniped
which lived during the Miocene
epoch about 21 to 24 million years ago. Approximately a metre (three feet) in length, the animal possessed only minimal physical adaptations for swimming. Unlike modern pinnipeds, it did not have flipper
s and its overall form was otter
-like, albeit more specialized; its skull and teeth are the features that most clearly indicate that it is a seal. It is considered to be the most primitive member of the seal family yet found. The genus name is an Inuktitut
word for a young seal; the species name honours the English
naturalist
Charles Darwin
. The one known specimen is a nearly complete fossilised skeleton. It is being housed at the Canadian Museum of Nature
in Ottawa
, Ontario
.
which represents a morphological
link in early pinniped
evolution. Its fossil remains demonstrate the presence of enlarged, probably webbed feet, robust forelimbs and an unspecialized tail. This suggests that Puijila swam quadrupedally using its webbed fore and hind feet for propulsion. Phylogenetic studies including molecular evidence suggest a sister relationship between pinnipeds (seals) and ursoids (bears) as well as musteloids (weasels and otters). It had been popularly assumed that land-dwelling mammals had at some point transitioned to a more marine existence, in essence "returning to the sea" in order to gain some sort of survival advantage. However, fossil evidence of this transition had been weak or contentious. The discovery of Puijila is important as it represents a morphological link in early pinniped evolution, and one that appears morphologically, to precede the more familiarly structured Enaliarctos
genus, despite apparently being a younger genus. In other words, Puijila is a transitional fossil
that provides information about how the seal family returned to the seas, similar to the way that Archaeopteryx
illuminates the origin of modern birds.
This novel species was discovered in 2007
by Natalia Rybczynski
and her team using surface collection and screening at an early Miocene lake deposit of the Haughton Formation of Devon Island
in Nunavut
, Canada
. The palaeobotanical record suggests that the palaeoenvironment around the lake comprised a forest community transitional between a boreal and a conifer–hardwood forest, in a cool temperate, coastal climate with moderate winters. Puijila darwini is the first mammalian carnivore found in the Haughton lake deposits. This also gives an indication that the entire pinniped family may have originated in the Arctic
.
The initial find is credited to field assistant Elizabeth Ross, and was partly a matter of luck
. Ross had been unexpectedly stranded with the team's ATV which had run out of fuel several kilometers away from base camp. The brain case was discovered a year later on the first day of the 2008 field expedition by Martin Lipman, the team's photographer.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of pinniped
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
which lived during the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
epoch about 21 to 24 million years ago. Approximately a metre (three feet) in length, the animal possessed only minimal physical adaptations for swimming. Unlike modern pinnipeds, it did not have flipper
Flipper (anatomy)
A flipper is a typically flat limb evolved for movement through water. Various creatures have evolved flippers, for example penguins , cetaceans A flipper is a typically flat limb evolved for movement through water. Various creatures have evolved flippers, for example penguins (also called...
s and its overall form was otter
Otter
The Otters are twelve species of semi-aquatic mammals which feed on fish and shellfish, and also other invertebrates, amphibians, birds and small mammals....
-like, albeit more specialized; its skull and teeth are the features that most clearly indicate that it is a seal. It is considered to be the most primitive member of the seal family yet found. The genus name is an Inuktitut
Inuktitut
Inuktitut or Eastern Canadian Inuktitut, Eastern Canadian Inuit language is the name of some of the Inuit languages spoken in Canada...
word for a young seal; the species name honours the English
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
naturalist
Naturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
. The one known specimen is a nearly complete fossilised skeleton. It is being housed at the Canadian Museum of Nature
Canadian Museum of Nature
The Canadian Museum of Nature is a natural history museum in Ottawa, Ontario, Canada. Its collections, which were started by the Geological Survey of Canada in 1856, include all aspects of the intersection of human society and nature, from gardening to gene-splicing...
in Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
, Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
.
Background
Puijila darwini was a semi-aquatic carnivoreCarnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
which represents a morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
link in early pinniped
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
evolution. Its fossil remains demonstrate the presence of enlarged, probably webbed feet, robust forelimbs and an unspecialized tail. This suggests that Puijila swam quadrupedally using its webbed fore and hind feet for propulsion. Phylogenetic studies including molecular evidence suggest a sister relationship between pinnipeds (seals) and ursoids (bears) as well as musteloids (weasels and otters). It had been popularly assumed that land-dwelling mammals had at some point transitioned to a more marine existence, in essence "returning to the sea" in order to gain some sort of survival advantage. However, fossil evidence of this transition had been weak or contentious. The discovery of Puijila is important as it represents a morphological link in early pinniped evolution, and one that appears morphologically, to precede the more familiarly structured Enaliarctos
Enaliarctos
Enaliarctos is an extinct genus of pinniped.Prior to the discovery of Puijila, the five species in the genus Enaliarctos represented the oldest known pinniped fossils, having been recovered from late Oligocene and early Miocene strata of California and Oregon.It had a short tail and developed...
genus, despite apparently being a younger genus. In other words, Puijila is a transitional fossil
Transitional fossil
A transitional fossil is any fossilized remains of a lifeform that exhibits characteristics of two distinct taxonomic groups. A transitional fossil is the fossil of an organism near the branching point where major individual lineages diverge...
that provides information about how the seal family returned to the seas, similar to the way that Archaeopteryx
Archaeopteryx
Archaeopteryx , sometimes referred to by its German name Urvogel , is a genus of theropod dinosaur that is closely related to birds. The name derives from the Ancient Greek meaning "ancient", and , meaning "feather" or "wing"...
illuminates the origin of modern birds.
Discovery
2007 in paleontology
-newly named:-New taxa:-Newly named non-avian dinosaurs:Data courtesy of George Olshevky's dinosaur genera list.-Newly named birds:-New papers:...
by Natalia Rybczynski
Natalia Rybczynski
Natalia Rybczynski, Ph.D., is a Canadian paleobiologist, professor and researcher.She is a research scientist with the Canadian Museum of Nature and holds a professorship at Carleton University in Ottawa...
and her team using surface collection and screening at an early Miocene lake deposit of the Haughton Formation of Devon Island
Devon Island
Devon Island , claimed to be the largest uninhabited island on Earth, is located in Baffin Bay, Qikiqtaaluk Region, Nunavut, Canada. It is one of the larger members of the Canadian Arctic Archipelago, the second-largest of the Queen Elizabeth Islands, Canada's sixth largest island, and the 27th...
in Nunavut
Nunavut
Nunavut is the largest and newest federal territory of Canada; it was separated officially from the Northwest Territories on April 1, 1999, via the Nunavut Act and the Nunavut Land Claims Agreement Act, though the actual boundaries had been established in 1993...
, 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 palaeobotanical record suggests that the palaeoenvironment around the lake comprised a forest community transitional between a boreal and a conifer–hardwood forest, in a cool temperate, coastal climate with moderate winters. Puijila darwini is the first mammalian carnivore found in the Haughton lake deposits. This also gives an indication that the entire pinniped family may have originated in the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
.
The initial find is credited to field assistant Elizabeth Ross, and was partly a matter of luck
Serendipity
Serendipity means a "happy accident" or "pleasant surprise"; specifically, the accident of finding something good or useful without looking for it. The word has been voted as one of the ten English words hardest to translate in June 2004 by a British translation company. However, due to its...
. Ross had been unexpectedly stranded with the team's ATV which had run out of fuel several kilometers away from base camp. The brain case was discovered a year later on the first day of the 2008 field expedition by Martin Lipman, the team's photographer.
External links
- Puijila darwini website
- Natalia Rybczynski at the Canadian Museum of Nature
- Brian Switek, Puijila darwini: A Significant Seal.
- Robert Boessenecker, Puijila, a very basal 'pinnipedimorph'.
- Ed Yong, Puijila, the walking seal — a beautiful transitional fossil.
- "Fossil seal had the feet of an otter" by Bob Holmes, New ScientistNew ScientistNew Scientist is a weekly non-peer-reviewed English-language international science magazine, which since 1996 has also run a website, covering recent developments in science and technology for a general audience. Founded in 1956, it is published by Reed Business Information Ltd, a subsidiary of...
, 25 April, 2009, p. 10.