Pelagornis
Encyclopedia
Pelagornis is a widely-known genus
of the prehistoric pseudotooth birds. 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.
have been formally described, but several other named taxa of pseudotooth birds might belong in Pelagornis too. The type species
Pelagornis miocaenus is known from Aquitanian
(Early Miocene
) sediments – formerly believed to be of Middle Miocene
age – of Armagnac
(France
). The original specimen on which P. miocaenus was founded was a left humerus
almost the size of a human arm. The scientific name – "the most unimaginative name ever applied to a fossil" in the view of Storrs L. Olson
– does in no way refer to the bird's startling and at that time unprecedented proportions, and merely means "Miocene
pelagic bird". Like many pseudotooth birds, it was initially believed to be related to the albatross
es in the tube-nosed seabird
s (Procellariiformes
), but subsequently placed in the Pelecaniformes
where it was either placed in the cormorant
and gannet
suborder (Sulae) or united with other pseudotooth birds in a suborder Odontopterygia.
While P. miocaenus was the first pseudotooth bird species to be described scientifically, its congener
Pelagornis mauretanicus was only named in 2008. It was a slightly distinct and markedly younger species. Its remains have been found in 2.5 Ma Gelasian
(Late Pliocene/Early Pleistocene
, MN17) deposits at Ahl al Oughlam
(Morocco
).
Additional fossil
s are placed in Pelagornis, usually without assignment to species, mainly due to their large size and Miocene age. From the USA, such specimens have been found in the Middle Miocene Calvert Formation of Maryland
and Virginia
, and in the contemporary Pungo River Formation of the Lee Creek Mine in North Carolina
(though at least one other pelagornithid is probably represented among this material too). USNM 244174 (a tarsometatarsus
fragment) was found near Charleston, South Carolina
and assigned to P. miocaenus, and the slightly smaller left tarsometatarsal middle trochlea
USNM 476044 might also belong here. A broken but fairly complete sternum
probably of this genus, specimen LHNB (CCCP)-1, is known from the Serravallian
-Tortonian
boundary (Middle to Late Miocene
) near Costa da Caparica
in Portugal
. Contemporary are certain specimens
from the Bahía Inglesa Formation of Chile
, while other material from this formation as well as remains from the Pisco Formation of Peru are from the Late Miocene to Early Pliocene. It is not clear whether the South America
n fossils – of similar size and age and not including directly comparable bones – are from one or two species. A very worn sternum and some other remains from the Miocene of Oregon
as well as roughly contemporary material from California
are sometimes assigned to Pelagornis, but this appears to be an error; if not of the contemporary North Pacific Osteodontornis
, the specimen is better regarded as indeterminable. Given the distance in space and time involved, all Pacific material may well have been a species different from P. miocaenus or even from birds closer to Osteodontornis. Indeed, some of the older Bahía Inglesa Formation remains tentatively referred to Pelagornis were at first assigned to the mysterious Pseudodontornis longirostris in error, and a proximal (initially misidentified as distal) humerus piece (CMNZ AV 24,960), from the Waiauan (Middle-Late Miocene) cliffs near the mouth of the Waipara River
(North Canterbury, New Zealand
) seems to differ little from either O. orri or P. miocaenus. The Pisco Formation specimens – which may be from the same species as the Bahía Inglesa ones, or from its direct descendant – on the other hand seem to be well distinct from Osteodontornis. It must be remembered, however, that the Isthmus of Panama
had not been formed yet during the Miocene.
The fossil specimens show that P. miocaenus was one of the large pseudotooth birds, hardly less in size than Osteodontornis or the older Dasornis
. Its head must have been about 40 cm (15.7 in) long in life, and its wingspan was probably more than 5 m (16.4 ft), perhaps closer to 6 m (20 ft). Unlike in its contemporary Osteodontornis but like in the older Pseudodontornis
, between each two of Pelagorniss large "teeth" was a single smaller one. Pelagornis differed from Dasornis and its smaller contemporary Odontopteryx
in having no pneumatic foramen in the fossa pneumotricipitalis of the humerus
, a single long latissimus dorsi muscle
attachment site on the humerus instead of two distinct segments, and no prominent ligamentum collateralis ventralis attachment knob on the ulna
. Further differences between Odontopteryx and Pelagornis are found in the tarsometatarsus
: in the latter, it has a deep fossa
of the hallux
' first metatarsal bone
, whereas its middle-toe trochlea
is not conspicuously expanded forward. The salt gland
s inside the eye sockets were extremely large and well-developed in Pelagornis. From the humerus pieces of specimen LACM 127875, found in the Eo
-Oligocene
Pittsburg Bluff Formation near Mist, Oregon
(USA), P. miocaenus differs in a external tuberosity that is not as much extended shoulderwards and that is separated from the elbow
end by a wider depression. Palmar
ly, the humerus head is turned more to the inward side and the large protuberance found there is not as far towards the end. The Waipara River humerus mentioned above agrees with P. miocaenus in that respect. If the Oregon fossils are related to Cyphornis
and/or Osteodontornis, and if the traits as found in P. miocaenus and the New Zealand specimen are apomorphic, the latter two may indeed be very close relatives.
y of P. miocaenus, neither does it seem to be a validly established taxon
nor was the specimen compared with P. miocaenus remains. It seems to refer to one of the syntype
s of the procellariiform Plotornis delfortrii – found at Léognan
(France) and also of Aquitanian age – from which that species was described in the 1870s by Alphonse Milne-Edwards
: when the nomen nudum
"Pelagornis delfortrii" is listed in the synonymy of P. miocaenus, the pseudotooth bird is claimed to be known from the Léognan deposits also, whereas it has not actually been found there. Pseudodontornis
, meanwhile, is a generally Paleogene
genus of huge pseudotooth birds. All its species are not uncommonly considered synonymous with earlier-described taxa. The (probably) Eo
-Oligocene
type species
Pseudodontornis longirostris might belong in Pelagornis, though given its uncertain age and provenance a comparison with undisputed Pelagornis material – which is currently lacking – would seem to be necessary before such a step is taken. In that respect, Palaeochenoides mioceanus was also hypothesized to include P. longirostris, and would need to be compared with Pelagornis to see whether it does not belong here too.
There has been little dedicated study of the relationships of Pelagornis, for while quite a lot of remains are known from the present genus, those of most other pseudotooth birds are few and far between and direct comparisons are further hampered by the damaged state of most remains. The large Gigantornis eaglesomei from the Middle Eocene Atlantic was established based on a broken but not too incomplete sternum
and might actually belong in Dasornis
. In Gigantornis the articular facet
for the furcula
consists of a flat section at the very tip of the sternal keel and a similar one set immediately above it at an outward angle, and the spina externa is shaped like an Old French shield in cross-section. The slightly smaller LHNB (CCCP)-1 has a less sharply protruding sternal keel, the articular facet for the furcula consists of a large knob at the forward margin, and the spina externa is narrow in cross-section. While these differences are quite conspicuous, the two fossils are clearly of closely related huge dynamically-soaring
seabird
s, and considering the 30 million years or so that separate Gigantornis and LHNB (CCCP)-1, the Paleogene taxon may be very close to the Miocene bird's ancestor nonwithstanding their differences.
In any case, the family
name of the pseudotooth birds, Pelagornithidae, as the senior synonym has widely replaced the once-commonly used Pseudodontornithidae. It may be that Pseudodontornis belongs to a distinct lineage of these birds, and then the family name would perhaps be revalidated. Also, the presumed similarity between Dasornis and the smaller Odontopteryx
seems to be a symplesiomorphy that is not informative regarding their relationships to each other and with Pelagornis. Rather, it is likely that the huge pseudotooth birds form a clade
, and in this case, Pseudodontornithidae like Cyphornithidae and Dasornithidae is correctly placed in the synonymy of Pelagornithidae even if several families were accepted in the Odontopterygiformes.
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. 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.
Description
Three 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...
have been formally described, but several other named taxa of pseudotooth birds might belong in Pelagornis 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...
Pelagornis miocaenus is known from Aquitanian
Aquitanian age
The Aquitanian is, in the ICS' geologic timescale, the oldest age or lowest stage in the Miocene. It spans the time between 23.03 ± 0.05 Ma and 20.43 ± 0.05 Ma and is a dry, cooling period...
(Early Miocene
Early Miocene
The Early Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages....
) sediments – formerly believed to be of Middle Miocene
Middle Miocene
The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene....
age – of Armagnac
Armagnac (region)
The hilly countship of Armagnac , in the foothills of the Pyrenées between the Adour and Garonne rivers, is a historic countship of the Duchy of Gascony, established in 601 in Aquitaine...
(France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
). The original specimen on which P. miocaenus was founded was a left humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
almost the size of a human arm. The scientific name – "the most unimaginative name ever applied to a fossil" in the view of Storrs L. Olson
Storrs L. Olson
Storrs Lovejoy Olson is an American biologist and ornithologist from the Smithsonian Institution. He is one of the world's foremost avian paleontologists....
– does in no way refer to the bird's startling and at that time unprecedented proportions, and merely means "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...
pelagic bird". Like many pseudotooth birds, it was initially believed to be related to the albatross
Albatross
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 the tube-nosed 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 (Procellariiformes
Procellariiformes
Procellariiformes is an order of seabirds that comprises four families: the albatrosses, petrels and shearwaters, storm petrels, and diving petrels...
), but subsequently placed in the 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...
where it was either placed in the 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 :...
and 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...
suborder (Sulae) or united with other pseudotooth birds in a suborder Odontopterygia.
While P. miocaenus was the first pseudotooth bird species to be described scientifically, its congener
Congener
Congener has several different meanings depending on the field in which it is used. Colloquially, it is used to mean a person or thing like another, in character or action.-Biology:In biology, congeners are organisms within the same genus...
Pelagornis mauretanicus was only named in 2008. It was a slightly distinct and markedly younger species. Its remains have been found in 2.5 Ma Gelasian
Gelasian
The Gelasian is an age in the international geologic timescale or a stage in chronostratigraphy, being the earliest or lowest subdivision of the Quaternary period/system and Pleistocene epoch/series. It spans the time between 2.588 ± 0.005 Ma and 1.806 ± 0.005 Ma...
(Late Pliocene/Early Pleistocene
Early Pleistocene
Calabrian is a subdivision of the Pleistocene Epoch of the Geologic time scale. ~1.8 Ma.—781,000 years ago ± 5,000 years, a period of ~.The end of the stage is defined by the last magnetic pole reversal and plunge in to an ice age and global drying possibly colder and drier than the late Miocene ...
, MN17) deposits at Ahl al Oughlam
Ahl al Oughlam
Ahl al Oughlam is an archaeological site and palaeontological site just outside of Casablanca in Morocco. Discovered in 1985 and first excavated in 1989, Ahl al Oughlam is the richest late Neogene vertebrate locality of North Africa...
(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...
).
Additional fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s are placed in Pelagornis, usually without assignment to species, mainly due to their large size and Miocene age. From the USA, such specimens have been found in the Middle Miocene Calvert Formation of Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
and Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
, and in the contemporary Pungo River Formation of the Lee Creek Mine in North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
(though at least one other pelagornithid is probably represented among this material too). USNM 244174 (a 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...
fragment) was found near Charleston, South Carolina
Charleston, South Carolina
Charleston is the second largest city in the U.S. state of South Carolina. It was made the county seat of Charleston County in 1901 when Charleston County was founded. The city's original name was Charles Towne in 1670, and it moved to its present location from a location on the west bank of the...
and assigned to P. miocaenus, and the slightly smaller left tarsometatarsal middle 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...
USNM 476044 might also belong here. A broken but fairly complete sternum
Sternum
The sternum or breastbone is a long flat bony plate shaped like a capital "T" located anteriorly to the heart in the center of the thorax...
probably of this genus, specimen LHNB (CCCP)-1, is known from the Serravallian
Serravallian
The Serravallian is in the geologic timescale an age or a stage in the middle Miocene epoch/series, that spans the time between 13.65 ± 0.05 Ma and 11.608 ± 0.005 Ma...
-Tortonian
Tortonian
The Tortonian is in the geologic timescale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma . It follows the Serravallian and is followed by the Messinian....
boundary (Middle to Late Miocene
Late Miocene
The Late Miocene is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch....
) near Costa da Caparica
Costa da Caparica
Costa da Caparica is a Portuguese city and a parish, located in the municipality of Almada. It has a population of 11,707 inhabitants and a total area of 10.88 km². Costa da Caparica is a city since December 2004.-Beaches:...
in Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
. Contemporary are certain specimens
from the Bahía Inglesa Formation of Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, while other material from this formation as well as remains from the Pisco Formation of Peru are from the Late Miocene to Early Pliocene. It is not clear whether the South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
n fossils – of similar size and age and not including directly comparable bones – are from one or two species. A very worn sternum and some other remains from the Miocene of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
as well as roughly contemporary material from 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...
are sometimes assigned to Pelagornis, but this appears to be an error; if not of the contemporary North Pacific 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...
, the specimen is better regarded as indeterminable. Given the distance in space and time involved, all Pacific material may well have been a species different from P. miocaenus or even from birds closer to Osteodontornis. Indeed, some of the older Bahía Inglesa Formation remains tentatively referred to Pelagornis were at first assigned to the mysterious Pseudodontornis longirostris in error, and a proximal (initially misidentified as distal) humerus piece (CMNZ AV 24,960), from the Waiauan (Middle-Late Miocene) cliffs near the mouth of the Waipara River
Waipara River
The Waipara River is a river the South Island of New Zealand.The river passes through the small town of Waipara on its 45 kilometre southeastward journey to the Pacific Ocean at the Northern end of Pegasus Bay....
(North Canterbury, 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...
) seems to differ little from either O. orri or P. miocaenus. The Pisco Formation specimens – which may be from the same species as the Bahía Inglesa ones, or from its direct descendant – on the other hand seem to be well distinct from Osteodontornis. It must be remembered, however, that 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 during the Miocene.
The fossil specimens show that P. miocaenus was one of the large pseudotooth birds, hardly less in size than Osteodontornis or the older 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....
. Its head must have been about 40 cm (15.7 in) long in life, and its wingspan was probably more than 5 m (16.4 ft), perhaps closer to 6 m (20 ft). Unlike in its contemporary Osteodontornis but like in the older 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...
, between each two of Pelagorniss large "teeth" was a single smaller one. Pelagornis differed from Dasornis and its smaller contemporary Odontopteryx
Odontopteryx
Odontopteryx is a genus of the prehistoric pseudotooth birds or pelagornithids. 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 no 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 single long 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 instead of two distinct segments, and no prominent ligamentum collateralis ventralis attachment knob on 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...
. 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 latter, it has 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....
, whereas 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 not 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 extremely large and well-developed in Pelagornis. From the humerus pieces of specimen LACM 127875, found in the Eo
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...
-Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
Pittsburg Bluff Formation near Mist, Oregon
Mist, Oregon
Mist is an unincorporated community in Columbia County, Oregon, United States. It was named for the atmospheric conditions of the Nehalem Valley.On July 6, 2001, the Mist store, which was built in 1874, caught fire and was destroyed...
(USA), P. miocaenus differs in a external tuberosity that is not as much extended shoulderwards and that is separated from the elbow
Elbow
The human elbow is the region surrounding the elbow-joint—the ginglymus or hinge joint in the middle of the arm. Three bones form the elbow joint: the humerus of the upper arm, and the paired radius and ulna of the forearm....
end by a wider depression. Palmar
Palmar
Palmar may refer to:* a directional anatomical term of location* El Palmar de Troya, a small village near Utrera, in Andalusia, Spain* Palmar Sur , a town the Osa region, Puntarenas province, Costa Rica...
ly, the humerus head is turned more to the inward side and the large protuberance found there is not as far towards the end. The Waipara River humerus mentioned above agrees with P. miocaenus in that respect. If the Oregon fossils are related to Cyphornis
Cyphornis
Cyphornis 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.-Description:...
and/or Osteodontornis, and if the traits as found in P. miocaenus and the New Zealand specimen are apomorphic, the latter two may indeed be very close relatives.
Synonyms and relationships
A humerus from the Muséum d'Histoire naturelle de Bordeaux was labelled "Pelagornis Delfortrii 1869". Though the name from the label had been listed in the synonymSynonym
Synonyms are different words with almost identical or similar meanings. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy. The word comes from Ancient Greek syn and onoma . The words car and automobile are synonyms...
y of P. miocaenus, neither does it seem to be a validly established taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
nor was the specimen compared with P. miocaenus remains. It seems to refer to one of the syntype
Syntype
In biological nomenclature, a syntype is a term used to indicate a specimen with a special status.In zoological nomenclature, a syntype is defined as "Each specimen of a type series from which neither a holotype nor a lectotype has been designated [Arts. 72.1.2, 73.2, 74]. The syntypes...
s of the procellariiform Plotornis delfortrii – found at Léognan
Léognan
Léognan is a commune in the Gironde department in Aquitaine in southwestern France.-Population:Its inhabitants are called Léognanais.-Wine:It is located in the Graves area of the Bordeaux county, known for its red wine :...
(France) and also of Aquitanian age – from which that species was described in the 1870s by Alphonse Milne-Edwards
Alphonse Milne-Edwards
Alphonse Milne-Edwards was a French mammalologist, ornithologist and carcinologist. He was English in origin, the son of Henri Milne-Edwards and grandson of Bryan Edwards, a Jamaican planter who settled at Bruges .Milne-Edwards obtained a medical degree in 1859 and became assistant to his father...
: when the nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
"Pelagornis delfortrii" is listed in the synonymy of P. miocaenus, the pseudotooth bird is claimed to be known from the Léognan deposits also, whereas it has not actually been found there. 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...
, meanwhile, is a generally 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...
genus of huge pseudotooth birds. All its species are not uncommonly considered synonymous with earlier-described taxa. The (probably) Eo
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...
-Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
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...
Pseudodontornis longirostris might belong in Pelagornis, though given its uncertain age and provenance a comparison with undisputed Pelagornis material – which is currently lacking – would seem to be necessary before such a step is taken. In that respect, Palaeochenoides mioceanus was also hypothesized to include P. longirostris, and would need to be compared with Pelagornis to see whether it does not belong here too.
There has been little dedicated study of the relationships of Pelagornis, for while quite a lot of remains are known from the present genus, those of most other pseudotooth birds are few and far between and direct comparisons are further hampered by the damaged state of most remains. The large Gigantornis eaglesomei from the Middle Eocene Atlantic was established based on a broken but not too incomplete sternum
Sternum
The sternum or breastbone is a long flat bony plate shaped like a capital "T" located anteriorly to the heart in the center of the thorax...
and might actually belong in 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 Gigantornis the articular facet
Articular facet
An articular facet is a surface where two anatomical structures meet.-Structures with articular facets:* cricoid cartilage* lateral malleolus* medial malleolus* tubercle of rib...
for the furcula
Furcula
The ' is a forked bone found in birds, formed by the fusion of the two clavicles. In birds, its function is the strengthening of the thoracic skeleton to withstand the rigors of flight....
consists of a flat section at the very tip of the sternal keel and a similar one set immediately above it at an outward angle, and the spina externa is shaped like an Old French shield in cross-section. The slightly smaller LHNB (CCCP)-1 has a less sharply protruding sternal keel, the articular facet for the furcula consists of a large knob at the forward margin, and the spina externa is narrow in cross-section. While these differences are quite conspicuous, the two fossils are clearly of closely related huge dynamically-soaring
Dynamic soaring
Dynamic soaring is a flying technique used to gain energy by repeatedly crossing the boundary between air masses of significantly different velocity...
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, and considering the 30 million years or so that separate Gigantornis and LHNB (CCCP)-1, the Paleogene taxon may be very close to the Miocene bird's ancestor nonwithstanding their differences.
In any case, the 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...
name of the pseudotooth birds, Pelagornithidae, as the senior synonym has widely replaced the once-commonly used Pseudodontornithidae. It may be that Pseudodontornis belongs to a distinct lineage of these birds, and then the family name would perhaps be revalidated. Also, the presumed similarity between Dasornis and the smaller Odontopteryx
Odontopteryx
Odontopteryx is a genus of the prehistoric pseudotooth birds or pelagornithids. 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....
seems to be a symplesiomorphy that is not informative regarding their relationships to each other and with Pelagornis. Rather, it is likely that the huge pseudotooth birds form a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
, and in this case, Pseudodontornithidae like Cyphornithidae and Dasornithidae is correctly placed in the synonymy of Pelagornithidae even if several families were accepted in the Odontopterygiformes.
External links
- Photo of some Calvert Formation specimens (and some of the disputed Oregon fossils) at National Museum of Natural HistoryNational Museum of Natural HistoryThe National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. Admission is free and the museum is open 364 days a year....
. Retrieved 2009-AUG-21. - From the collections, Part 4 - Article on Calvert Formation material of ?Pelagornis sp. 2. at Virginia Museum of Natural HistoryVirginia Museum of Natural HistoryVirginia Museum of Natural History is the state's natural history museum located in Martinsville founded in 1984. The museums has several different award winning publications is affiliated with the Smithsonian Institution, and has more than 22 million items...
Retrieved 2010-SEP-18.