Eogruidae

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Eogruidae
Temporal range: Late Eocene–Early Pliocene
Ergilornis.jpg
Detailed depiction of Ergilornis in its habitat
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Infraclass: Palaeognathae
Order: Struthioniformes
Family: Eogruidae
Wetmore, 1934
Genera

Eogruidae (also spelled Eogruiidae in some publications) is a family of large, flightless birds that inhabited Asia from the Eocene to Pliocene epochs. Related to modern ostriches, it was formerly thought to be related to cranes, limpkins and trumpeters and that the similarities with ostriches were due to similar speciations to cursoriality, with both groups showing reduced numbers of toes to two in some taxa. [1] [2] [3] It has been suggested that competition from true ostriches has caused the extinction of these birds, [2] [3] though this has never been formally tested and several ostrich taxa do occur in the late Cenozoic of Asia [4] and some species do occur in areas where ostrich fossils have also been found. [1] It has been suggested that the family is paraphyletic, with Ergilornithidae more closely related to modern ostriches than to Eogrus or Sonogrus . [5]

Contents

Description

Most eogruids are known from rather sparse remains, mostly the tarso-metatarsals and toes. The former are generally slender with a distinct crest along the lateral side of the plantar surface. The trochlea for the second toe shows a progressive reduction along the various taxa, culminating in its utter absence in Amphipelargus. [4] [3]

Other skeletal remains are rare. Wing elements are known in a few taxa; these are generally highly reduced, suggesting that these birds were flightless. The exception appears to be Eogrus itself, which does not show much phalange reduction and hypothetically could still fly, [4] though the rest of the postcranial skeleton is already specialised for cursoriality. [2] [3]

Classification

Eogruids were formerly considered to be Gruiformes within the crane-limpkin-trumpeter line, Gruoidea, the exception being Olson 1985 which declared them to be stem-ostriches. [4] A study in 2021 based on newly described remains found that eogruids and the related Ergilornithidae are indeed members of Struthoniformes. [6]

More derived taxa such as Ergilornis and Amphipelargus were sometimes classified as a separate family, Ergilornithidae, but they are now generally accepted to be a subfamily within Eogruidae. [1] Eogruids are rather similar to Geranoididae, a clade of similar flightless gruiforms from North America and Europe, and both groups have occasionally been classified as sister taxa. Recently geranoidids have been recovered as basal to the rest of Gruoidea, however, while eogruids are sister-taxa to cranes. [7]

Taxonomy

There is some contention in regards to ergilornithine genera, particularly Amphipelargus and Urmiornis, which have assimilated each other's species from study to study. The most recent consensus is that nearly all Neogene eogruid remains belong to Urmiornis, while a few western Eurasian taxa can be referred to as Amphipelargus. [1]

Related Research Articles

<span class="mw-page-title-main">Struthioniformes</span> Order of birds

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, including a variety of flightless forms like the Paleotididae, Geranoididae, Eogruidae and Ergilornithidae, the latter two thought to be closely related to Struthionidae.

<span class="mw-page-title-main">Gruiformes</span> Order of birds

The Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like".

<span class="mw-page-title-main">Rail (bird)</span> Family of birds

The rails, or Rallidae, are a large cosmopolitan family of small- to medium-sized, ground-living birds. The family exhibits considerable diversity and includes the crakes, coots, and gallinules. Many species are associated with wetlands, although the family is found in every terrestrial habitat except dry deserts, polar regions, and alpine areas above the snow line. Members of the Rallidae occur on every continent except Antarctica. Numerous island species are known. The most common rail habitats are marshland and dense forest. They are especially fond of dense vegetation.

<span class="mw-page-title-main">Struthionidae</span> Family of birds

Struthionidae is a family of flightless birds, containing the extant ostriches and their extinct relatives. The two extant species of ostrich are the common ostrich and Somali ostrich, both in the genus Struthio, which also contains several species known from Holocene fossils such as the Asian ostrich. The common ostrich is the more widespread of the two living species, and is the largest living bird species. The extinct genus Pachystruthio from the Late Pliocene-Early Pleistocene of Eurasia is one of the largest birds ever.

<span class="mw-page-title-main">Ostrich</span> Genus of flightless birds

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 two living species of ostrich: the common ostrich, native to large areas of sub-Saharan Africa and the Somali ostrich, native to the Horn of Africa. The common ostrich was also historically native to the Arabian Peninsula, and ostriches were present across Asia as far east as Mongolia during the Late Pleistocene and possibly into the Holocene. They lay the largest eggs of any living land animal. With the ability to run at 70 km/h (43.5 mph), they are the fastest birds on land. They are farmed worldwide, particularly for their feathers as they are used as decoration and feather dusters. Their skin is also used for leather products. They are the heaviest living birds.

<span class="mw-page-title-main">Adzebill</span> Extinct genus of birds

The adzebills, genus Aptornis, were two closely related bird species, the North Island adzebill,, and the South Island adzebill,, of the extinct family Aptornithidae. The family was endemic to New Zealand. A fossil species,, is known from the Miocene Saint Bathans fauna.

<span class="mw-page-title-main">Palaeognathae</span> Infraclass of birds

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 contains five extant branches of flightless lineages, termed ratites, and one flying lineage, the Neotropic tinamous. There are 47 species of tinamous, five of kiwis (Apteryx), three of cassowaries (Casuarius), one of emus (Dromaius), two of rheas (Rhea) and two of ostriches (Struthio). Recent research has indicated that paleognaths are monophyletic but the traditional taxonomic split between flightless and flighted forms is incorrect; tinamous are within the ratite radiation, meaning flightlessness arose independently multiple times via parallel evolution.

<i>Palaeotis</i> Extinct genus of birds

Palaeotis is a genus of paleognath birds from the middle Eocene epoch of central Europe. One species is known, Palaeotis weigelti. The holotype specimen is a fossil tarsometatarsus and phalanx. Lambrect (1928) described it as an extinct bustard, and gave it its consequent name. 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 as ostriches; the Struthioniformes. 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.

Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1976.

Macrodontopteryx is a genus of the prehistoric pseudotooth birds of somewhat doubtful validity. These animals 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.

<i>Lithornis</i> Extinct genus of birds

Lithornis is a genus of extinct paleognathous birds. Although Lithornis was able to fly well, their closest relatives are the extant tinamous and ratites.

<span class="mw-page-title-main">Lithornithidae</span> Extinct family of birds

Lithornithidae is an extinct, possibly paraphyletic group of early paleognath birds. They are known from fossils dating to the Upper Paleocene through the Middle Eocene of North America and Europe, with possible Late Cretaceous representatives. All are extinct today; the youngest specimen is the currently unnamed SGPIMH MEV1 specimen from the mid-Eocene Messel Pit site.

<i>Messelornis</i> Extinct genus of birds

Messelornis, also known as the Messel rail, is an extinct genus of gruiform bird, closely related to modern rails. It is the most abundant bird from the Messel Lagerstätte, representing roughly half of all Messel bird fossils with more than 500 specimens known. The fossil record are from the Paleocene to the early Eocene.

<span class="mw-page-title-main">Palaelodidae</span> Extinct family of birds

Palaelodidae is a family of extinct birds in the group Phoenicopteriformes, which today is represented only by the flamingos. They were widespread during the Neogene, with fossil remains found on all continents other than Antarctica. The oldest remains referred to this group appeared in the fossil record during the Oligocene in Egypt and Belgium, before palaelodids reached their peak diversity during the Miocene. Following this the group declined in the early Pliocene before going extinct on most continents. However remains found near Cooper Creek in the Lake Eyre Basin indicate that palaelodids managed to survive in Australia until the Pleistocene. Currently three genera are recognized by scientists: Adelalopus, Palaelodus and Megapaloelodus. Most fossil remains stem from Europe and have been assigned to the type species, Palaelodus ambiguus. Due to the fragmentary nature of most of these species, little is known about their ecology. They appear to have prefered brackish lakes and lagoons. Palaelodus has previously been thought to be a wader or diver, but recent research indicates that they were better suited for swimming and possibly fed on insect larvae and other aquatic invertebrates. At least Megapaloelodus appears to have adaptations for "locking" their legs in a standing position.

<span class="mw-page-title-main">Gruimorphae</span> Clade of birds

Gruimorphae is a clade of birds that contains the orders Charadriiformes and Gruiformes identified by molecular analysis. This grouping has had historical support, as various charadriiform families such as the families Pedionomidae and Turnicidae were classified as gruiforms. It may also have support from the fossil record since the discovery of Nahmavis from the Early Eocene of North America.

<span class="mw-page-title-main">Bathornithidae</span> Extinct family of birds

Bathornithidae is an extinct family of birds from the Eocene to Miocene of North America. Part of Cariamiformes, they are related to the still extant seriemas and the also extinct Phorusrhacidae. They were likely similar in habits, being terrestrial, long-legged predators, some of which attained massive sizes.

Eutreptornis is a genus of extinct possible cariamiforme bird from the Late Eocene of Utah. It is traditionally considered to be a bathornithid, though a combination of the relative incompleteness of the material alongside some differences from other bathornithids have raised some suspicions about this affiliation.

<i>Bathornis</i> Extinct genus of birds

Bathornis is an extinct lineage of birds related to modern day seriemas, that lived in North America about 37–20 million years ago. Like the closely related and also extinct phorusrhacids, it was a flightless predator, occupying predatory niches in environments classically considered to be dominated by mammals. It was a highly diverse and successful genus, spanning a large number of species that occurred from the Priabonian Eocene to the Burdigalian Miocene epochs.

Geranoididae is a clade of extinct birds from the early to late Eocene and possibly early Oligocene of North America and Europe. These were mid-sized, long-legged flightless birds. Recent research shows that these birds may actually be palaeognaths related to ostriches.

<span class="mw-page-title-main">Messelornithidae</span>

Messelornithidae is an extinct clade of gruiform birds, closely related to modern rails. The fossil record are from the Paleocene to the early Oligocene of Europe and North America.

References

  1. 1 2 3 4 5 Zelenkov, Nikita; Boev, Zlatozar; Lazaridis, Georgios (2016). "A large ergilornithine (Aves, Gruiformes) from the Late Miocene of the Balkan Peninsula". Paläontologische Zeitschrift. 90: 145–151. doi:10.1007/s12542-015-0279-z. S2CID   131264199.
  2. 1 2 3 Kurochkin, E.N. 1976. A survey of the Paleogene birds of Asia. Smithsonian Contributions to Paleobiology 27:75-86.
  3. 1 2 3 4 Kurochkin, E.N. 1981. New representatives and evolution of two archaic gruiform families in Eurasia. Transactions of the Soviet-Mongolian Paleontologial Expedition 15:59-85.
  4. 1 2 3 4 Mayr, G. (2009). Paleogene fossil birds. Springer.
  5. Mayr, Gerald; Zelenkov, Nikita (2021-11-13). "Extinct crane-like birds (Eogruidae and Ergilornithidae) from the Cenozoic of Central Asia are indeed ostrich precursors". Ornithology. 138 (4): ukab048. doi: 10.1093/ornithology/ukab048 . ISSN   0004-8038.
  6. Mayr, G. & Zelenkov, N. (2021) Extinct crane-like birds (Eogruidae and Ergilornithidae) from the Cenozoic of Central Asia are indeed ostrich precursors. Ornithology, https://doi.org/10.1093/ornithology/ukab048
  7. Mayr, Gerald (2016). "On the taxonomy and osteology of the Early Eocene North American Geranoididae (Aves, Gruoidea)". Swiss Journal of Palaeontology. 135 (2): 315–325. doi:10.1007/s13358-016-0117-2. S2CID   87692869.