''Palaeotis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomencla ...

paleognath Palaeognathae (; ) is a infraclass of birds, called paleognaths, within the class Aves of the clade Archosauria. It is one of the two extant infraclasses of birds, the other being Neognathae, both of which form Neornithes. Palaeognathae conta ...

birds from the middle

Eocene epoch 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'', "daw ...

of central Europe. One species is known, ''Palaeotis weigelti''. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen is a fossil

tarsometatarsus The tarsometatarsus is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) and met ...

and

phalanx The phalanx ( grc, φάλαγξ; plural phalanxes or phalanges, , ) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar pole weapons. The term is particularly ...

. Lambrect (1928) described it as an extinct

bustard Bustards, including floricans and korhaans, are large, terrestrial birds living mainly in dry grassland areas and on the steppes of the Old World. They range in length from . They make up the family Otididae (, formerly known as Otidae). Bustard ...

(genus ''Otis''), and gave it its consequent name (''Palaeotis'' means ''ancient bustard'').Lambrecht, K. (1928) ''Palaeotis weigelti n. g. sp., eine fossil trappe aus der mitteleozanen Braunkohle des Geiseltales. Jahrbuch hallesch. Verband., Halle, n.s., 7:11. After a suggestion by Storrs L. Olson, a review of the type specimen and the referral of several other fossils by Houde and Haubold (1987) concluded that ''Palaeotis'' is a palaeognath and assigned it to the same

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 ...

ostrich Ostriches are large flightless birds of the genus ''Struthio'' in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, and kiwis. There are ...

es; the

Struthioniformes Struthioniformes is an order of birds with only a single extant family, Struthionidae, containing the ostriches. Several other extinct families are known, spanning across the Northern Hemisphere, from the Early Eocene to the early Pliocene, includ ...

.Houde, Peter. Haubold, Hartmut. (1987) Palaeovertebrata, 17 (2): 27 - 46, 6 figures. 20 June 1987. In 2021, it was considered a member of the family Paleotididae alongside '' Galligeranoides'' from the Early Eocene of France, which were found to be basal members of the Struthioniformes. Palaeotis weigelti 2

In the 1930s a nearly complete fossil with catalog number GM 4362 was assigned to ''Palaeotis'', probably by Lambrecht. Houde and Haubold found three additional specimens in the collection of the Geiseltalmuseum, Martin-Luther University, Halle/S., Germany. One of those three is the holotype specimen of ''Paleogrus geiseltalensis'' (=Ornithocnemus geiseltalensis, Lambrecht 1935). Houde and Haubold also requested permission to prepare a fossil cataloged as HLMD Me 7530 at the Hesseches Landesmuseum in Darmstadt, Germany. HLMD Me 7530 was collected from the famous

Messel shales The Messel pit (german: Grube Messel) is a disused quarry near the village of Messel (Landkreis Darmstadt-Dieburg, Hesse) about southeast of Frankfurt am Main, Germany. Bituminous shale was mined there. Because of its abundance of well-preserve ...

. When it was prepared, the two ornithologists assigned it to Palaeotis as well. Other scientists are less convinced that Palaeotis is a struthioniform, placing it instead as a more basal

ratite A ratite () is any of a diverse group of flightless, large, long-necked, and long-legged birds of the infraclass Palaeognathae. Kiwi, the exception, are much smaller and shorter-legged and are the only nocturnal extant ratites. The systematics o ...

. It may be related to the mysterious '' Remiornis'', a putative ratite known from the

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'', "daw ...

of France. Various other ratite remains also occur in the European Paleogene and early Miocene, and these may represent various independent linages, leading to further confusion.

Biology

''Palaeotis'' is suggested to be sexually dimorphic, as some specimens being consistently smaller than others. While the forelimb is incomplete, the spindley humerus indicates that it had relatively large wings unlike modern

ostriches Ostriches are large flightless birds of the genus ''Struthio'' in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, and kiwis. There are ...

and

rheas The rheas ( ), also known as ñandus ( ) or South American ostriches, are large ratites (flightless birds without a keel on their sternum bone) in the order Rheiformes, native to South America, distantly related to the ostrich and emu. Most tax ...

. The beak was slender, more similar to that of lithornithids, and probably had similar carnivorous habits. ''Paleotis'' is considered to be

flightless Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species, including the well known ratites (ostriches, emu, cassowaries, rheas, and kiwi) and penguins. The smallest flightless bird is the In ...

References

Eocene birds of Europe Struthioniformes {{paleo-bird-stub