Macrodontopteryx
Encyclopedia
Macrodontopteryx is a genus
of the prehistoric pseudotooth birds of somewhat doubtful validity. These animals 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.
, Macrodontopteryx oweni, is known to date. Its remains were found in the Ypresian
(Early Eocene) London Clay
of the Isle of Sheppey
(England
), where they were deposited about 50 Ma (million years ago) in the Mammal Paleogene zone
MP8-9. The fossil
s were at first assigned to Argillornis longipennis, which is nowadays recognized as junior synonym of Dasornis emuinus
, a larger pseudotooth bird than M. oweni. Due to the scarcity of their fossil remains, is not clear whether the pseudotooth bird species described as Pseudodontornis longidentata
is not the same as M. oweni, though its size suggests that it is more likely to be synonymous with D. emuinus. In any case, Macrodontopteryx itself may well be no distinct genus but rather a large member of the contemporary and sympatric Odontopteryx
, or a young or small Dasornis.
The only known specimen (BMNH A1) is an incomplete and rather crushed skull
with much all of the beak
missing. In the living animal it would have measured roughly 30–35 cm (one foot). The wingspan
was probably around 4 m (13.1 ft).
(Middle Eocene, MP11-13
, about 45 Ma) deposits at Etterbeek
(Belgium
) belong therein. Like the holotype
BMNH A1, they have been assigned to Argillornis longipennis in the past; at least some of the material placed in that taxon
at one time or another – but not its syntype
humerus
pieces – seems too small to be of an adult Dasornis.
An Early Oligocene (Stampian, MP21-23, about 32 Ma) distal radius
from Hamstead, Isle of Wight
(England) was also assigned to Macrodontopteryx. It is without doubt from a very large and flight-capable bird, but little else can be said about it. An equally old cervical vertebra fragment (specimen BMNH A-4413) and a toe phalanx from nearby Yarmouth
were, mainly due to their size, believed to be related to the enigmatic large flightless bird (and presumed ratite
) Eleutherornis. They were described as Proceriavis martini, but have never been compared in detail to pseudotooth bird fossils. It cannot be ruled out that Proceriavis belongs in the Pelagornithidae, but whether it would be a junior synonym of Macrodontopteryx is highly uncertain given the 20-million-year difference between the Isle of Sheppey and Isle of Wight material.
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 of somewhat doubtful validity. These animals 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
Only a single 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...
, Macrodontopteryx oweni, is known to date. Its remains were found in 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...
), where they were deposited about 50 Ma (million years ago) in the Mammal Paleogene zone
Mammal Paleogene zone
The Mammal Paleogene zones or MP zones are biostratigraphic zones in the stratigraphic record of the Paleogene period of Europe. These zones were developed by Matthijs Freudenthal to help paleontologists provide more specific reference points to evolutionary events in Europe, but are used by...
MP8-9. The fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s were at first assigned to Argillornis longipennis, which is nowadays recognized as junior synonym of Dasornis emuinus
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....
, a larger pseudotooth bird than M. oweni. Due to the scarcity of their fossil remains, is not clear whether the pseudotooth bird species described as Pseudodontornis longidentata
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...
is not the same as M. oweni, though its size suggests that it is more likely to be synonymous with D. emuinus. In any case, Macrodontopteryx itself may well be no distinct genus but rather a large member of the contemporary and sympatric 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....
, or a young or small Dasornis.
The only known specimen (BMNH A1) is an incomplete and rather crushed 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...
with much all of the beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
missing. In the living animal it would have measured roughly 30–35 cm (one foot). The 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...
was probably around 4 m (13.1 ft).
Other supposed remains
If Macrodontopteryx is indeed a distinct genus, perhaps some pseudotooth bird fossils found in LutetianLutetian
The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between and . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the Middle Eocene subepoch...
(Middle Eocene, MP11-13
Mammal Paleogene zone
The Mammal Paleogene zones or MP zones are biostratigraphic zones in the stratigraphic record of the Paleogene period of Europe. These zones were developed by Matthijs Freudenthal to help paleontologists provide more specific reference points to evolutionary events in Europe, but are used by...
, about 45 Ma) deposits at Etterbeek
Etterbeek
Etterbeek is one of the nineteen municipalities located in the Brussels-Capital Region of Belgium. It neighbours the municipalities of the City of Brussels, Ixelles, Auderghem, Woluwe-Saint-Pierre, Woluwe-Saint-Lambert and Schaerbeek....
(Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
) belong therein. Like 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...
BMNH A1, they have been assigned to Argillornis longipennis in the past; at least some of the material placed in that 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...
at one time or another – but not its 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...
humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
pieces – seems too small to be of an adult Dasornis.
An Early Oligocene (Stampian, MP21-23, about 32 Ma) distal radius
Radius (bone)
The radius is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna, which exceeds it in length and size. It is a long bone, prism-shaped and slightly curved longitudinally...
from Hamstead, Isle of Wight
Hamstead, Isle of Wight
Hamstead is a village on the Isle of Wight. It is located about three miles east of Yarmouth, in the northwest of the island....
(England) was also assigned to Macrodontopteryx. It is without doubt from a very large and flight-capable bird, but little else can be said about it. An equally old cervical vertebra fragment (specimen BMNH A-4413) and a toe phalanx from nearby Yarmouth
Yarmouth, Isle of Wight
Yarmouth is a port and civil parish in the western part of the Isle of Wight, off the southern coast of mainland England. The town is named for its location at the mouth of the small Western Yar river...
were, mainly due to their size, believed to be related to the enigmatic large flightless bird (and presumed ratite
Ratite
A ratite is any of a diverse group of large, flightless birds of Gondwanan origin, most of them now extinct. Unlike other flightless birds, the ratites have no keel on their sternum—hence the name from the Latin ratis...
) Eleutherornis. They were described as Proceriavis martini, but have never been compared in detail to pseudotooth bird fossils. It cannot be ruled out that Proceriavis belongs in the Pelagornithidae, but whether it would be a junior synonym of Macrodontopteryx is highly uncertain given the 20-million-year difference between the Isle of Sheppey and Isle of Wight material.