Odontopteryx
Encyclopedia
Odontopteryx is a genus
of the prehistoric pseudotooth birds or pelagornithids. These were probably rather close relatives of either pelican
s and stork
s, or of waterfowl
, and are here placed in the order
Odontopterygiformes to account for this uncertainty.
of Odontopteryx has been formally described, but several other named taxa of pseudotooth birds might belong here too. The type species
Odontopteryx toliapica is known from the Ypresian
(Early Eocene) London Clay
of the Isle of Sheppey
(England
) and slightly older rocks of the Ouled Abdoun Basin (Morocco
). Its tarsometatarsus
(e.g. specimen BMNH
A4962) was for some time in the late 20th century believed to be from a giant procellariiform and called Neptuniavis minor, but specimen BMNH A44096 – the holotype
skull described by Richard Owen
in 1873 – was the first pelagornithid recognized as such, and not assigned to some other seabird
lineage. It was still often allied with Sulidae
(boobies and gannets) or Diomedeidae (albatrosses), to which it is quite certainly not closely related.
One to five (or perhaps more) additional unnamed species are tentatively assigned to the present genus, mainly due to their size and/or forward-angled "teeth": one smaller and one larger than O. toliapica and also from the Late Paleocene or Early Eocene of the Ouled Abdoun Basin in Morocco, one from the mid-Eocene
of Uzbekistan
, one from Middle Eocene strata of the Tepetate Formation from near El Cien (Baja California Sur
, Mexico
), and one from the Early Eocene of Virginia, USA. As regards the Moroccan fossils, however, the largest of the three Odontopteryx-like forms (initially called "Odontopteryx n. sp. 2") has provisionally been termed "Odontopteryx gigas" but may in fact be a Dasornis
, while the smallest ("Odontopteryx n. sp. 1") has been considered a distinct genus (as "Odontoptila inexpectata") but that name is both a nomen nudum
and would in any case be a junior homonym of the geometer moth
genus Odontoptila
and thus unavailable for the bird. Though the Mexican specimen (MHN-UABCS Te5/6–517, a distal humerus
piece) agrees with O. toliapica in size and shape, it is not entirely clear whether the American
forms belong in this otherwise Eurasia
n genus. It must be remembered, however, that at that their time the Isthmus of Panama
had not been formed yet.
Pseudodontornis tschulensis
from the Late Paleocene of Zhylga (Kazakhstan
) is sometimes placed in Odontopteryx, as is Macrodontopteryx oweni which was also found in the London Clay. In the latter case however, this does not seem to be correct (see below). The species originally described as O. longirostris was made the type species of Pseudodontornis
in 1930. Small pelagornithid specimens have also been reported from the Early Oligocene Kishima Group
and the Late Oligocene Ashiya Group of Japan
, but their placement in Odontopteryx is even more uncertain.
"Neptuniavis" minor was described from remains assigned to O. toliapica by Richard Lydekker
in 1891. However, the supposed procellariiform genus Neptunavis is actually a pseudotooth bird too, and hence the smaller "species" is here synonymized as proposed by Lydekker. The type species
"N." miranda, on the other hand, is a junior synonym of the large Dasornis emuinus. In a peculiar twist, some material assigned to "N." minor eventually turned out to be remains of the paleognath Lithornis vulturinus; the very first described bone of Dasornis emuinus on the other hand – a humerus
piece – was at first mistaken for to be a Lithornis
tarsometatarsus.
es in wingspan
and the Brown Pelican
(Pelecanus occidentalis) in bulk. In life, its head (including the beak) would have been 20–25 cm (8–10 in) long. Unlike in most other pseudotooth birds, its "teeth" are slanted forwards.
Like those of its relatives, the thin-walled bones of Odontopteryx broke easily and thus very few fossil
s – though still far more than of the average pseudotooth bird genus – are decently preserved. In combination with its small (for pseudotooth birds) size, some traits allow to identify the present genus. It resembles Dasornis
in having a jugal
arch that is mid-sized, tapering and stout behind the orbit
al process of the prefrontal bone
, unlike in the large Neogene
Osteodontornis
. Also, its paroccipital process is much elongated back- and downwards, again like in Dasornis but unlike in Pseudodontornis longirostris. Meanwhile, the distal humerus
specimen from Mexico
(MHN-UABCS Te5/6–517) which may or may not belongs in the present genus differs from the corresponding bone of Osteodontornis in a more narrow and less excavated surface between the external condyle and the ectepicondylar prominence, with the pit between these closer to the bone's end. Its quadrate bone
, meanwhile, differed from that of Osteodontornis in a very broadly grooved dorsal
head, a wide main shaft with a strongly curved lateral ridge and a small and somewhat forward-pointing orbit
al process. The forward center of the quadrate's ventral articulation ridge extends downwards and to the middle, and the pterygoid process is only slightly expanded to the upper center in Odontopteryx. The socket for the quadratojugal
is displaced downwards. The quadrate of P. longirostris is not very well-preserved; it agees with Odontopteryx in a broad main shaft but is closer to Osteodontornis in the straight main shaft ridge and its upward-directed ventral articulation ridge's forward center. Its quadratojugal socket differs from both.
Odontopteryx differed from Pelagornis
(a contemporary of Osteodontornis) and agreed with Dasornis in having a deep and long handward-pointing pneumatic foramen in the fossa pneumotricipitalis of the humerus
, a latissimus dorsi muscle
attachment site on the humerus that consists of two distinct segments instead of a single long, and a large knob that extends along the ulna
where the ligamentum collateralis ventralis attached. Further differences between Odontopteryx and Pelagornis are found in the tarsometatarsus
: in the present genus, it lacks a deep fossa
of the hallux
' first metatarsal bone
and its middle toe trochlea
is conspicuously expanded forward. The salt gland
s inside the eye sockets were far less developed in Odontopteryx than in Pelagornis. As the traits shared between Odontopteryx and Dasornis are probably plesiomorphic however, they cannot be used to argue for a closer relationship between the two Paleogene
genera than either had with Osteodontornis and/or Pelagornis.
But even though – due to the lack of better-preserved fossils – a close relationship between Odontopteryx and Dasornis cannot be excluded for sure either, it seems that the Neogene pseudotooth birds all derive from a large Paleogene form – such as Dasornis or (if it is not actually identical with Pelagornis) the mysterious P. longirostris – and that the smallish lineage became entirely extinct before the Neogene (perhaps in the Grande Coupure). In 1891 O. toliapica was proposed as type genus
of a family
Odontopterygidae; recent authors generally place all pseudotooth birds in a single family. But if the evolution
ary scenario outlined above is correct, the family name Pelagornithidae could be restricted to the giant lineage, and the Odontopterygidae reestablished as name for the smaller lineage. Macrodontopteryx was initially also included in the Odontopterygidae, but if not a distinct genus it is more likely a young individual of Dasornis. The only smallish Neogene pseudotooth bird known as of 2009 is "Pseudodontornis" stirtoni from New Zealand
, which was about the size of O. toliapica. Its relationships are completely obscure.
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 the prehistoric pseudotooth birds or pelagornithids. These were probably rather close relatives of either pelican
Pelican
A pelican, derived from the Greek word πελεκυς pelekys is a large water bird with a large throat pouch, belonging to the bird family Pelecanidae....
s and stork
Stork
Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family Ciconiidae. They are the only family in the biological order Ciconiiformes, which was once much larger and held a number of families....
s, or of waterfowl
Waterfowl
Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....
, and are here placed in the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Odontopterygiformes to account for this uncertainty.
Species and taxonomy
One speciesSpecies
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 Odontopteryx has been formally described, but several other named taxa of pseudotooth birds might belong here too. 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...
Odontopteryx toliapica is known from the Ypresian
Ypresian
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between and , is preceded by the Thanetian age and is followed by the Eocene Lutetian age....
(Early Eocene) London Clay
London Clay
The London Clay Formation is a marine geological formation of Ypresian age which crops out in the southeast of England. The London Clay is well known for the fossils it contains. The fossils from the Lower Eocene indicate a moderately warm climate, the flora being tropical or subtropical...
of the Isle of Sheppey
Isle of Sheppey
The Isle of Sheppey is an island off the northern coast of Kent, England in the Thames Estuary, some to the east of London. It has an area of . The island forms part of the local government district of Swale...
(England
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...
) and slightly older rocks of the Ouled Abdoun Basin (Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
). Its tarsometatarsus
Tarsometatarsus
The tarsometatarsus is a bone that is found in the lower leg of certain tetrapods, namely birds.It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsal and metatarsal bones...
(e.g. specimen BMNH
BMNH
BMNH may refer to:*British Museum of Natural History, commonly known as Natural History Museum, in London, the United Kingdom*Beijing Museum of Natural History, in Beijing, China...
A4962) was for some time in the late 20th century believed to be from a giant procellariiform and called Neptuniavis minor, but specimen BMNH A44096 – the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
skull described by Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
in 1873 – was the first pelagornithid recognized as such, and not assigned to some other 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...
lineage. It was still often allied with Sulidae
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...
(boobies and gannets) or Diomedeidae (albatrosses), to which it is quite certainly not closely related.
One to five (or perhaps more) additional unnamed species are tentatively assigned to the present genus, mainly due to their size and/or forward-angled "teeth": one smaller and one larger than O. toliapica and also from the Late Paleocene or Early Eocene of the Ouled Abdoun Basin in Morocco, one from 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...
of Uzbekistan
Uzbekistan
Uzbekistan , officially the Republic of Uzbekistan is a doubly landlocked country in Central Asia and one of the six independent Turkic states. It shares borders with Kazakhstan to the west and to the north, Kyrgyzstan and Tajikistan to the east, and Afghanistan and Turkmenistan to the south....
, one from Middle Eocene strata of the Tepetate Formation from near El Cien (Baja California Sur
Baja California Sur
Baja California Sur , is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. Before becoming a state on October 8, 1974, the area was known as the South Territory of Baja California. It has an area of , or 3.57% of the land mass of Mexico and comprises...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
), and one from the Early Eocene of Virginia, USA. As regards the Moroccan fossils, however, the largest of the three Odontopteryx-like forms (initially called "Odontopteryx n. sp. 2") has provisionally been termed "Odontopteryx gigas" but may in fact be a Dasornis
Dasornis
Dasornis is a genus of the prehistoric pseudotooth birds. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty....
, while the smallest ("Odontopteryx n. sp. 1") has been considered a distinct genus (as "Odontoptila inexpectata") but that name is both a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
and would in any case be a junior homonym of the geometer moth
Geometer moth
The geometer moths or Geometridae are a family of the order Lepidoptera...
genus Odontoptila
Odontoptila
Odontoptila is a moth genus in the family Geometridae.-References:*...
and thus unavailable for the bird. Though the Mexican specimen (MHN-UABCS Te5/6–517, a distal humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
piece) agrees with O. toliapica in size and shape, it is not entirely clear whether the American
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
forms belong in this otherwise Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
n genus. It must be remembered, however, that at that their time the Isthmus of Panama
Isthmus of Panama
The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country of Panama and the Panama Canal...
had not been formed yet.
Pseudodontornis tschulensis
Pseudodontornis
Pseudodontornis is a rather disputed genus of the prehistoric pseudotooth birds. The pseudotooth birds or pelagornithids were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty...
from the Late Paleocene of Zhylga (Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
) is sometimes placed in Odontopteryx, as is Macrodontopteryx oweni which was also found in the London Clay. In the latter case however, this does not seem to be correct (see below). The species originally described as O. longirostris was made the type species of Pseudodontornis
Pseudodontornis
Pseudodontornis is a rather disputed genus of the prehistoric pseudotooth birds. The pseudotooth birds or pelagornithids were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty...
in 1930. Small pelagornithid specimens have also been reported from the Early Oligocene Kishima Group
Kishima Group
The Kishima Group is a group of palaeontological formations located in Japan. It dates to the Upper Eocene - Lower Oligocene period.The formations of the Kishima Group are:* Daimyoji Formation* Funazu Formation* Itanoura Formation...
and the Late Oligocene Ashiya Group of 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...
, but their placement in Odontopteryx is even more uncertain.
"Neptuniavis" minor was described from remains assigned to O. toliapica by Richard Lydekker
Richard Lydekker
Richard Lydekker was an English naturalist, geologist and writer of numerous books on natural history.-Biography:...
in 1891. However, the supposed procellariiform genus Neptunavis is actually a pseudotooth bird too, and hence the smaller "species" is here synonymized as proposed by Lydekker. 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...
"N." miranda, on the other hand, is a junior synonym of the large Dasornis emuinus. In a peculiar twist, some material assigned to "N." minor eventually turned out to be remains of the paleognath Lithornis vulturinus; the very first described bone of Dasornis emuinus on the other hand – a humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
piece – was at first mistaken for to be a Lithornis
Lithornis
Lithornis is a genus of extinct paleognathous birds. Lithornis were able to fly well, but are closely related to today's tinamous and ratites ....
tarsometatarsus.
Description and systematics
O. toliapica is among the smallest pseudotooth birds known to date – but this still means that to would have rivalled, if not exceeded, most living albatrossAlbatross
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes . They range widely in the Southern Ocean and the North Pacific...
es in wingspan
Wingspan
The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...
and the Brown Pelican
Brown Pelican
The Brown Pelican is the smallest of the eight species of pelican, although it is a large bird in nearly every other regard. It is in length, weighs from and has a wingspan from .-Range and habits:...
(Pelecanus occidentalis) in bulk. In life, its head (including the beak) would have been 20–25 cm (8–10 in) long. Unlike in most other pseudotooth birds, its "teeth" are slanted forwards.
Like those of its relatives, the thin-walled bones of Odontopteryx broke easily and thus very few fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s – though still far more than of the average pseudotooth bird genus – are decently preserved. In combination with its small (for pseudotooth birds) size, some traits allow to identify the present genus. It resembles Dasornis
Dasornis
Dasornis is a genus of the prehistoric pseudotooth birds. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty....
in having a jugal
Jugal
The jugal is a skull bone found in most reptiles, amphibians, and birds. In mammals, the jugal is often called the malar or Zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species....
arch that is mid-sized, tapering and stout behind the orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
al process of the prefrontal bone
Prefrontal bone
The prefrontal bone is a bone separating the lacrimal and frontal bones in many tetrapod skulls. It first evolved in the sarcopterygian clade Rhipidistia, which includes lungfish and the Tetrapodomorpha. The prefrontal is found in most modern and extinct lungfish, amphibians and reptiles...
, unlike in the large Neogene
Neogene
The Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago...
Osteodontornis
Osteodontornis
Osteodontornis is an extinct seabird genus. It contains a single named species, Osteodontornis orri , which was described quite exactly one century after the first species of the Pelagornithidae was. O...
. Also, its paroccipital process is much elongated back- and downwards, again like in Dasornis but unlike in Pseudodontornis longirostris. Meanwhile, the distal humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
specimen from Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
(MHN-UABCS Te5/6–517) which may or may not belongs in the present genus differs from the corresponding bone of Osteodontornis in a more narrow and less excavated surface between the external condyle and the ectepicondylar prominence, with the pit between these closer to the bone's end. Its quadrate bone
Quadrate bone
The quadrate bone is part of a skull in most tetrapods, including amphibians, sauropsids , and early synapsids. In these animals it connects to the quadratojugal and squamosal in the skull, and forms part of the jaw joint .- Evolutionary variation :In snakes, the quadrate bone has become elongated...
, meanwhile, differed from that of Osteodontornis in a very broadly grooved dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
head, a wide main shaft with a strongly curved lateral ridge and a small and somewhat forward-pointing orbit
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents...
al process. The forward center of the quadrate's ventral articulation ridge extends downwards and to the middle, and the pterygoid process is only slightly expanded to the upper center in Odontopteryx. The socket for the quadratojugal
Quadratojugal
The quadratojugal is a small jaw bone that is present in most amphibians, reptiles, and birds, but has been lost in mammals. It is connected to the jugal as well as other bones, though these may vary with species....
is displaced downwards. The quadrate of P. longirostris is not very well-preserved; it agees with Odontopteryx in a broad main shaft but is closer to Osteodontornis in the straight main shaft ridge and its upward-directed ventral articulation ridge's forward center. Its quadratojugal socket differs from both.
Odontopteryx differed from Pelagornis
Pelagornis
Pelagornis is a widely-known genus of the prehistoric pseudotooth birds. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty....
(a contemporary of Osteodontornis) and agreed with Dasornis in having a deep and long handward-pointing pneumatic foramen in the fossa pneumotricipitalis of the humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
, a latissimus dorsi muscle
Latissimus dorsi muscle
The latissimus dorsi , meaning 'broadest muscle of the back' , is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region.The latissimus dorsi is responsible for extension,...
attachment site on the humerus that consists of two distinct segments instead of a single long, and a large knob that extends along the ulna
Ulna
The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form...
where the ligamentum collateralis ventralis attached. Further differences between Odontopteryx and Pelagornis are found in the tarsometatarsus
Tarsometatarsus
The tarsometatarsus is a bone that is found in the lower leg of certain tetrapods, namely birds.It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsal and metatarsal bones...
: in the present genus, it lacks a deep fossa
Fossa (anatomy)
In anatomical terminology, fossa has come to mean a depression or hollow, in general, in a bone. Other parts of the body may be involved, for example, the antecubital fossa...
of the hallux
Hallux
In tetrapods, the hallux is the innermost toe of the foot. Despite its name it may not be the longest toe on the foot of some individuals...
' first metatarsal bone
First metatarsal bone
The first metatarsal bone is the bone in the body of the foot just behind the big toe.It is remarkable for its great thickness, and is the shortest of the metatarsal bones.The body is strong, and of well-marked prismoid form....
and its middle toe trochlea
Trochlea
Trochlea is a term in anatomy. It refers to a grooved structure reminiscent of a pulley's wheel.Most commonly, trochleae bear the articular surface of saddle and other joints:* Trochlea of humerus* Trochlear process of the Calcaneus...
is conspicuously expanded forward. The salt gland
Salt gland
The salt gland is an organ for excreting excess salts. It is found in elasmobranchs, seabirds, and some reptiles. In sharks, salt glands are found in the rectum, but in birds and reptiles, they are found in or on the skull, in the area of the eyes, nostrils or mouth. In crocodiles, the salt is...
s inside the eye sockets were far less developed in Odontopteryx than in Pelagornis. As the traits shared between Odontopteryx and Dasornis are probably plesiomorphic however, they cannot be used to argue for a closer relationship between the two Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
genera than either had with Osteodontornis and/or Pelagornis.
But even though – due to the lack of better-preserved fossils – a close relationship between Odontopteryx and Dasornis cannot be excluded for sure either, it seems that the Neogene pseudotooth birds all derive from a large Paleogene form – such as Dasornis or (if it is not actually identical with Pelagornis) the mysterious P. longirostris – and that the smallish lineage became entirely extinct before the Neogene (perhaps in the Grande Coupure). In 1891 O. toliapica was proposed as type genus
Type genus
In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...
of a 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...
Odontopterygidae; recent authors generally place all pseudotooth birds in a single family. But if the evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
ary scenario outlined above is correct, the family name Pelagornithidae could be restricted to the giant lineage, and the Odontopterygidae reestablished as name for the smaller lineage. Macrodontopteryx was initially also included in the Odontopterygidae, but if not a distinct genus it is more likely a young individual of Dasornis. The only smallish Neogene pseudotooth bird known as of 2009 is "Pseudodontornis" stirtoni from New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, which was about the size of O. toliapica. Its relationships are completely obscure.
Further reading
- The Rise of Birds: 225 Million Years of Evolution by Sankar Chatterjee
- The Origin and Evolution of Birds by Alan Feduccia
- Fossils (Smithsonian Handbooks) by David Ward
External links
- CorbisCorbisCorbis Corporation is an American company, based in Seattle, Washington, that licenses the rights to photographs, footage and other visual media...
: Photo of the holotypeHolotypeA holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
skull (BMNH A44096). Retrieved 2009-AUG-21.