''Gigantornis eaglesomei'' is a very large prehistoric bird described from a fragmentary specimen from the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

. It was originally described as a representative of the

albatross Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacifi ...

family, Diomedeidae, but was later referred to the pseudotooth or

bony-toothed bird The Pelagornithidae, commonly called pelagornithids, pseudodontorns, bony-toothed birds, false-toothed birds or pseudotooth birds, are a prehistoric family of large seabirds. Their fossil remains have been found all over the world in rocks datin ...

family, Pelagornithidae. ''Gigantornis'' is one of the largest pseudotooth birds, with an

inferred Inferences are steps in reasoning, moving from premises to logical consequences; etymologically, the word '' infer'' means to "carry forward". Inference is theoretically traditionally divided into deduction and induction, a distinction that i ...

wingspan of about 6 m (20 ft) it is among the largest birds ever. Its identified remains consist of a broken

sternum The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sh ...

found in

Middle Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn ...

Ameki Formation The Ameki Formation is a Lutetian to Bartonian geological formation located in Nigeria. It belongs to the Bende-Ameki Group. Ameki Formation is also a group that consists of two formations namely Nnanka Formation, Nsugbe Formation. Fossil cont ...

deposits at Ameki (

). The

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

bird was considered to belong the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

(Diomedeidae), as no sterna of pseudotooth birds were known until its discovery, and it remained the only such specimen for decades. Only in the 1970s its true affinities were realized, after it had become clear that although it must have been from a dynamic soarer with wings like an albatross, it resembled pelicans (

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Ciconiiformes) rather than

tubenoses Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are oft ...

(order Procellariiformes, to which albatrosses belong) in its details. It is not known whether this bird belongs to a distinct genus; it might even be the very same species as the similar-sized ''

Dasornis emuinus ''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. Alm ...

'', whose fossils are not uncommon in the

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

(Early Eocene)

London Clay The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 million years ago) age which crops out in the southeast of England. The London Clay is well known for its fossil content. The fossils from t ...

of the

Isle of Sheppey The Isle of Sheppey is an island off the northern coast of Kent, England, neighbouring the Thames Estuary, centred from central London. It has an area of . The island forms part of the local government district of Swale. ''Sheppey'' is derived ...

(

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

). Remains of a large pseudotooth bird were also found in the Middle Eocene of Kpogamé-Hahotoé (

Togo Togo (), officially the Togolese Republic (french: République togolaise), is a country in West Africa. It is bordered by Ghana to the west, Benin to the east and Burkina Faso to the north. It extends south to the Gulf of Guinea, where its c ...

) and have been provisionally termed " Aequornis traversei"; their analysis is likely to provide at least some insight on the

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

status of ''G. eaglesomei''. The ''Gigantornis'' sternum is of the typical short and deep-crested shape found in dynamic soarers. Compared to LHNB (CCCP)-1, a Middle to

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

pseudotooth bird sternum found in

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

and tentatively assigned to ''

Pelagornis ''Pelagornis'' is a widespread genus of 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 uncertain ...

'', its

articular facet A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

for the

furcula The (Latin for "little fork") or wishbone is a forked bone found in most birds and some species of non-avian dinosaurs, and is formed by the fusion of the two pink clavicles. In birds, its primary function is in the strengthening of the thoracic ...

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.Mayr ''et al.'' (2008)

Footnotes

References

* Andrews, C.W. (1916): Note on the sternum of a large carinate bird from the Eocene of Southern Nigeria. ''Proceedings of the Zoological Society of London'' 1916: 519–524. * Bourdon, Estelle (2005): Osteological evidence for sister group relationship between pseudo-toothed birds (Aves: Odontopterygiformes) and waterfowls (Anseriformes). ''

Naturwissenschaften ''The Science of Nature'', formerly ''Naturwissenschaften'', is a monthly peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of the natural sciences relating to questions of biological significance. I ...

'' 92(12): 586–591. (HTML abstract
Electronic supplement
(requires subscription) * Bourdon, Estelle (2006): L'avifaune du Paléogène des phosphates du Maroc et du Togo: diversité, systématique et apports à la connaissance de la diversification des oiseaux modernes (Neornithes) Paleogene avifauna of phosphates of Morocco and Togo: diversity, systematics and contributions to the knowledge of the diversification of the Neornithes" Doctoral thesis,

Muséum national d'histoire naturelle The French National Museum of Natural History, known in French as the ' (abbreviation MNHN), is the national natural history museum of France and a ' of higher education part of Sorbonne Universities. The main museum, with four galleries, is loc ...

n French N, or n, is the fourteenth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''en'' (pronounced ), plural ''ens''. History ...

br>HTML abstract
* Brodkorb, Pierce (1963): Catalogue of fossil birds. Part 1 (Archaeopterygiformes through Ardeiformes). ''Bulletin of the Florida State Museum, Biological Sciences'' 7(4): 179–293
PDF or JPEG fulltext
*

International Commission on Zoological Nomenclature The International Commission on Zoological Nomenclature (ICZN) is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 26 commissioners from 20 countries. Orga ...

(ICZN) (1999): ''International Code of Zoological Nomenclature'' (4th ed.). International Trust for Zoological Nomenclature, London. HTML fulltext
* Mayr, Gerald (2009): ''Paleogene Fossil Birds''. Springer-Verlag, Heidelberg & New York. * Mayr, Gerald; Hazevoet, Cornelis J.; Dantas, Pedro; & Cachāo, Mário (2008): A sternum of a very large bony-toothed bird (Pelagornithidae) from the Miocene of Portugal. '' J. Vertebr. Paleontol.'' 28(3): 762–769. DOI:10.1671/0272-4634(2008)28 62:ASOAVL.0.CO;2HTML abstract
* Olson, Storrs L. (1985): The Fossil Record of Birds. ''In:'' Farner, D.S.; King, J.R. & Parkes, Kenneth C. (eds.): ''Avian Biology'' 8: 79-252
PDF fulltext
{{Taxonbar, from=Q5560236 Pelagornithidae Eocene birds Eocene animals of Africa Prehistoric bird genera