Plotopteridae
Encyclopedia
Plotopteridae is the name of an extinct family
of flightless seabird
s from the order Pelecaniformes
. Related to the gannet
s and boobies
, they exhibited remarkable convergent evolution
with the penguin
s, particularly with the now extinct giant penguins. That they lived in the North Pacific, the other side of the world from the penguins, has led to them being described at times as the Northern Hemisphere's penguins, although one new theory suggests that this group is a link between the penguins and the Pelecaniformes. Their fossil
s have been found in California
, Washington and Japan
. They ranged in size from that of a large cormorant
(such as a Brandt's Cormorant
), to being 2 m long. They had shortened wings designed for underwater wing-propelled pursuit diving (like penguins or the now extinct Great Auk
), a body skeleton
similar to that of the darter
and the skull
similar to that of a sulid
.
The earliest known Plotopteridae species, Phocavis maritimus lived in the mid-Eocene
, but most of the known species lived in the early and mid-Miocene
, after which it appears they went extinct. That they went extinct at the same time as the giant penguins
of the Southern Hemisphere, which also coincided with the radiation of the seal
s and dolphin
s, has led to speculation that the expansion of marine mammal
s was responsible for the extinction of the Plotopteridae.
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...
of flightless seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s from the order Pelecaniformes
Pelecaniformes
The Pelecaniformes is a order of medium-sized and large waterbirds found worldwide. As traditionally—but erroneously—defined, they encompass all birds that have feet with all four toes webbed. Hence, they were formerly also known by such names as totipalmates or steganopodes...
. Related to the gannet
Gannet
Gannets are seabirds comprising the genus Morus, in the family Sulidae, closely related to the boobies.The gannets are large black and white birds with yellow heads. They have long pointed wings and long bills. Northern gannets are the largest seabirds in the North Atlantic, with a wingspan of up...
s and boobies
Booby
A booby is a seabird in the genus Sula, part of the Sulidae family. Boobies are closely related to the gannets , which were formerly included in Sula.-Description:...
, they exhibited remarkable convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
with the penguin
Penguin
Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...
s, particularly with the now extinct giant penguins. That they lived in the North Pacific, the other side of the world from the penguins, has led to them being described at times as the Northern Hemisphere's penguins, although one new theory suggests that this group is a link between the penguins and the Pelecaniformes. Their fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s have been found in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Washington and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. They ranged in size from that of a large cormorant
Cormorant
The bird family Phalacrocoracidae is represented by some 40 species of cormorants and shags. Several different classifications of the family have been proposed recently, and the number of genera is disputed.- Names :...
(such as a Brandt's Cormorant
Brandt's Cormorant
The Brandt's Cormorant is a strictly marine bird of the cormorant family of seabirds that inhabits the Pacific coast of North America. It ranges, in the summer, from Alaska to the Gulf of California, but the population north of Vancouver Island migrates south during the winter...
), to being 2 m long. They had shortened wings designed for underwater wing-propelled pursuit diving (like penguins or the now extinct Great Auk
Great Auk
The Great Auk, Pinguinus impennis, formerly of the genus Alca, was a large, flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus Pinguinus, a group of birds that formerly included one other species of flightless giant auk from the Atlantic Ocean...
), a body skeleton
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
similar to that of the darter
Darter
The darters or snakebirds are mainly tropical waterbirds in the family Anhingidae. There are four living species, three of which are very common and widespread while the fourth is rarer and classified as near-threatened by the IUCN. The term "snakebird" is usually used without any additions to...
and the skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
similar to that of a sulid
Sulidae
The bird family Sulidae comprises the gannets and boobies. Collectively called sulidas, they are medium-large coastal seabirds that plunge-dive for fish and similar prey. The ten species in this family are often considered congeneric in older sources, placing all in the genus Sula...
.
The earliest known Plotopteridae species, Phocavis maritimus lived in the mid-Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
, but most of the known species lived in the early and mid-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...
, after which it appears they went extinct. That they went extinct at the same time as the giant penguins
Palaeeudyptinae
The New Zealand Giant Penguins, Palaeeudyptinae, are an extinct subfamily of penguins. It includes several genera of medium-sized to very large species - including Palaeeudyptes marplesi and Anthropornis nordenskjoeldi which grew tall or even larger, and the massive Pachydyptes ponderosus which...
of the Southern Hemisphere, which also coincided with the radiation of the seal
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...
s and dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
s, has led to speculation that the expansion of marine mammal
Marine mammal
Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
s was responsible for the extinction of the Plotopteridae.