Tympanoneisiotes
Encyclopedia
Tympanonesiotes is a somewhat doubtfully valid 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.
, Tympanonesiotes wetmorei, is known to date. The only known specimen (USNM 16809), a distal right tarsometatarsus
end, was found in the Cooper River
near Drum Island
at Charleston, South Carolina
(USA). At first it was believed to be from the Early Miocene
Hawthorne Formation, but as it seems its actual age cannot be precisely determined: For one thing, no Hawthorne Formation deposits were known in the region where the fossil was found. However, close to its type locality, fossil
s of Late Miocene
animals have been found reworked from a now-eroded
layer of rock into older deposits, such as the Chattian
(Late Oligocene) sediments of the Cooper or Chandler Bridge Formation where the specimen of T. wetmorei was presumably found. The much-worn pseudotooth bird bone may also be such a reworked specimen.
The genus' scientific name references the type locality: it is derived from Ancient Greek
tympanon (drum) + nesiotes (islander). The specific name honors the famous ornithologist Alexander Wetmore
; thus the scientific name means roughly "Alexander Wetmore's Drum Island bird".
e is still preserved in good detail however. Altogether, the bone is very similar to that of the sympatric and probably contemporary Palaeochenoides mioceanus, only appearing a bit more albatross
-like. The spread of the toes must have resembled that found in a fulmar
quite a lot, by contrast. The thin-walled bone has a second toe
trochlea that attaches notably kneewards from the others and is angled slightly outwards while the hallux
was vestigial or missing, as is typical for the pseudotooth birds. The fossil is about one-quarter smaller than that of Palaeochenoides, with a maximum end width of 24.5 mm (0.964566929133858 in) (as far as the trochleae are preserved), and a shaft that is 16.1 mm (0.633858267716536 in) wide near the point where it flares into the trochleae. It was thus about half again as large as "Odontoptila inexpectata" from the Late Paleocene/Early Eocene of the Ouled Abdoul Basin (Morocco
), i.e. around the size of the Early Eocene Odontopteryx toliapica from England
or slightly bigger, or about the size of a great albatross
(Diomedea) or our time. If the Tympanonesiotes fossil is indeed of Miocene age, it would be among the very few pseudotooth birds known from the Neogene
that was not of immense size.
family
Cyphornithidae, which had been placed in the "pelecaniform
" suborder Cladornithes, together with two other misidentified pseudotooth birds – Palaeochenoides and the family's type genus
Cyphornis
. The type genus
of that supposed suborder, the enigmatic Late Oligocene Cladornis from the Argentinian part of Patagonia
, like the present species is only known from a distal right tarsometatarsus end. This was believed to be reminiscent of the (then still undescribed) Tympanonesiotes, and thus it was argued that all four genera were closely related. But Cladornis is more generally held to be a terrestrial
bird of unclear affiliations rather than a seabird
nowadays, and the Cladornithes are not used anymore by recent authors.
As regards the supposed Cyphornithidae, most if not all all pseudotooth birds placed there are probably closely related to the better-known Pelagornis
, type genus
of the family Pelagornithidae. And even if Cyphornis is the senior synonym of Palaeochenoides and Tympanoneisiotes (which is not overly likely), according to the rules of zoological nomenclature the family name Pelagornithidae would not be affected. Thus Cyphornithidae would almost certainly be a junior synonym of Pelagornithidae even if the pseudotooth birds are (as some have proposed) divided into several families – rather than being all placed in the Pelagornithidae as is usual nowadays – as Cyphornis, Osteodontornis
, Palaeochenoides, Pelagornis and perhaps Tympanoneisiotes appear to be very closely related and are probably part of a monophyletic lineage of (usually) giant pseudotooth birds.
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.
Species and taxonomy
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...
, Tympanonesiotes wetmorei, is known to date. The only known specimen (USNM 16809), a distal right 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...
end, was found in the Cooper River
Cooper River (South Carolina)
The Cooper River is a mainly tidal river in the U.S. state of South Carolina. These cities are located along the river, Mt. Pleasant, Charleston, North Charleston, Goose Creek and Hanahan. Short and wide, it is joined first by the blackwater East Branch, then farther downstream, the tidal Wando River...
near Drum Island
Drum Island
Drum Island is a former Norwegian electronic music group from Tromsø, composed of Torbjørn Brundtland , Rune Lindbæk and Ole Johan Mjøs. Svein Berge and Gaute Barlindhaug are contributors. Their only release is a self-titled album released in 1997, along with two singles. The album was released on...
at 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...
(USA). At first it was believed to be from the 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....
Hawthorne Formation, but as it seems its actual age cannot be precisely determined: For one thing, no Hawthorne Formation deposits were known in the region where the fossil was found. However, close to its type locality, fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of 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....
animals have been found reworked from a now-eroded
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
layer of rock into older deposits, such as the Chattian
Chattian
The Chattian is, in the geologic timescale, the youngest of two ages or upper of two stages of the Oligocene epoch/series. It spans the time between and . The Chattian is preceded by the Rupelian and is followed by the Aquitanian .-Stratigraphic definition:The Chattian was introduced by Austrian...
(Late Oligocene) sediments of the Cooper or Chandler Bridge Formation where the specimen of T. wetmorei was presumably found. The much-worn pseudotooth bird bone may also be such a reworked specimen.
The genus' scientific name references the type locality: it is derived from Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
tympanon (drum) + nesiotes (islander). The specific name honors the famous ornithologist Alexander Wetmore
Alexander Wetmore
Frank Alexander Wetmore was an American ornithologist and avian paleontologist.-Life:Wetmore studied at the University of Kansas...
; thus the scientific name means roughly "Alexander Wetmore's Drum Island bird".
Description
The bone is not very well-preserved; for most of its length only the anterior surface remains. What remains of the trochleaTrochlea
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...
e is still preserved in good detail however. Altogether, the bone is very similar to that of the sympatric and probably contemporary Palaeochenoides mioceanus, only appearing a bit more 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...
-like. The spread of the toes must have resembled that found in a fulmar
Fulmar
Fulmars are seabirds of the family Procellariidae. The family consists of two extant species and two that are extinct.-Taxonomy:As members of Procellaridae and then the order Procellariiformes, they share certain traits. First, they have nasal passages that attach to the upper bill called...
quite a lot, by contrast. The thin-walled bone has a second toe
Toe
Toes are the digits of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being digitigrade. Humans, and other animals that walk on the soles of their feet, are described as being plantigrade; unguligrade animals are those that walk on hooves at the tips of...
trochlea that attaches notably kneewards from the others and is angled slightly outwards while 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...
was vestigial or missing, as is typical for the pseudotooth birds. The fossil is about one-quarter smaller than that of Palaeochenoides, with a maximum end width of 24.5 mm (0.964566929133858 in) (as far as the trochleae are preserved), and a shaft that is 16.1 mm (0.633858267716536 in) wide near the point where it flares into the trochleae. It was thus about half again as large as "Odontoptila inexpectata" from the Late Paleocene/Early Eocene of the Ouled Abdoul 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...
), i.e. around the size of the Early Eocene Odontopteryx toliapica from 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...
or slightly bigger, or about the size of a great albatross
Great albatross
The great albatrosses are seabirds in the genus Diomedea in the albatross family. The genus Diomedea formerly included all albatrosses except the sooty albatrosses, but in 1996 the genus was split with the mollymawks and the North Pacific albatrosses both being elevated to separate genera...
(Diomedea) or our time. If the Tympanonesiotes fossil is indeed of Miocene age, it would be among the very few pseudotooth birds known from the 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...
that was not of immense size.
Systematics
T. wetmorei was initially placed in the presumed pelecaniformPelecaniformes
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...
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...
Cyphornithidae, which had been placed in the "pelecaniform
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...
" suborder Cladornithes, together with two other misidentified pseudotooth birds – Palaeochenoides and the family's 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...
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:...
. The 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 that supposed suborder, the enigmatic Late Oligocene Cladornis from the Argentinian part of Patagonia
Patagonia
Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...
, like the present species is only known from a distal right tarsometatarsus end. This was believed to be reminiscent of the (then still undescribed) Tympanonesiotes, and thus it was argued that all four genera were closely related. But Cladornis is more generally held to be a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
bird of unclear affiliations rather than a 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...
nowadays, and the Cladornithes are not used anymore by recent authors.
As regards the supposed Cyphornithidae, most if not all all pseudotooth birds placed there are probably closely related to the better-known 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....
, 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 the family Pelagornithidae. And even if Cyphornis is the senior synonym of Palaeochenoides and Tympanoneisiotes (which is not overly likely), according to the rules of zoological nomenclature the family name Pelagornithidae would not be affected. Thus Cyphornithidae would almost certainly be a junior synonym of Pelagornithidae even if the pseudotooth birds are (as some have proposed) divided into several families – rather than being all placed in the Pelagornithidae as is usual nowadays – as Cyphornis, 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...
, Palaeochenoides, Pelagornis and perhaps Tympanoneisiotes appear to be very closely related and are probably part of a monophyletic lineage of (usually) giant pseudotooth birds.