Rhynchaeites

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Rhynchaeites
Temporal range: Early to Middle Eocene
Rhynchaeites sp.jpg
R. messelensis from Germany
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Pelecaniformes
Family: Threskiornithidae
Subfamily: Rhynchaeitinae
Mayr, 2002
Genus: Rhynchaeites
Wittich, 1898
Type species
Rhynchaeites messelensis
Wittich, 1898
Species
  • R. messelensisWittich, 1898
  • R. litoralis Mayr & Kitchener, 2023

Rhynchaeites is an extinct genus of wading bird, a stem-group threshkiornithid, from the Eocene. It is one of the oldest members of the ibis family known from fossil remains. [1]

Contents

Taxonomy

Life restoration of R. messelensis. Rhynchaeites restoration.jpg
Life restoration of R. messelensis.

The type species, R. messelensis, is known from many well-preserved specimens from the famous Lutetian-aged Messel pit of Germany. It was initially thought to represent an early relative of painted-snipes (family Rostratulidae), and was still considered an early charadriiform for nearly a century, but was identified as an early ibis in 1983. [1]

In 2023, a second species, R. litoralis was described from the earlier Ypresian-aged London Clay of England. R. litoralis is mostly known from isolated bones but also multiple partial skeletons. In addition to their differing morphologies, both species appear to have inhabited different habitats, with R. messelensis inhabiting freshwater habitats and R. litoralis coastal habitats. [1] [2]

An undescribed, largely complete Rhynchaeites specimen has been reported from the Green River Formation of the United States. [1] The potential leg bone fossils of Rhynchaeites have also been found in the earliest Ypresian Fur Formation in Denmark. It has been hypothesized that the supposed parrot relative Mopsitta tanta , known from a single humerus bone, is the same bird as the leg fossils and thus actually belongs in Rhynchaeites too. [1] [3]

Morphology

Rhynchaeites messelensis Rhynchaeites messelensis.jpg
Rhynchaeites messelensis

Despite its close resemblance to modern ibises, Rhynchaeites differs in several aspects of morphology from them, primarily in its much shorter legs and the apparent lack of any sensory nerves in its bill. The latter suggests that Rhynchaeites primarily relied on sight to find food, as opposed to the tactile probing of modern ibises. The short legs of Rhynchaeites appear to be a plesiomorphic trait, and suggest that long legs evolved multiple times within the Pelecaniformes. [1] [2]

Related Research Articles

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

The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills; however recent genetic studies have cast doubt on this arrangement, and have found the spoonbills to be nested within the Old World ibises, and the New World ibises as an early offshoot.

<span class="mw-page-title-main">Sunbittern</span> Species of bittern-like bird

The sunbittern is a bittern-like bird of tropical regions of the Americas, and the sole member of the family Eurypygidae and genus Eurypyga. It is found in Central and South America, and has three subspecies. The sunbittern shows both morphological and molecular similarities with the kagu of New Caledonia, indicating a Gondwanan origin, both species being placed in the clade Eurypygiformes.

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

Limnofregata is an extinct genus of primitive frigatebird. The two known species were described after fossils from the Early Eocene Green River Formation of Wyoming. A number of good complete and partial skeletons, some with feather impressions, are known of the type species, Limnofregata azygosternon, and L. hasegawai is known from two skulls and most of one torso.

Neogaeornis is a controversial prehistoric genus of diving bird. The single known species, Neogaeornis wetzeli, was described from fossils found in the Campanian to Maastrichtian Quiriquina Formation of Chile. It lived about 70-67 million years ago. It remains known from the single tarsometatarsus described in 1929 by Lambrecht, and today housed in the Paläontologisches Institut und Museum in Kiel, Germany.

Mopsitta tanta is an extinct bird of uncertain taxonomic position from the Early Eocene of Denmark; its remains were recovered from the Fur Formation. So far, the holotype and only known specimen is a single humerus bone of rather large size. Although the phylogenetic position of genus is unclear, it was initially presumed to be phylogenetically closer to Recent Psittacidae than to other known Palaeogene psittaciforms and may, therefore, represent the oldest known crown-group parrot.

Eurofluvioviridavis is a genus of extinct primitive birds from the Middle Eocene Messel Pit, Germany. It contains a single species, Eurofluvioviridavis robustipes. It is related to Avolatavis and Vastanavis, other members of the family Vastanavidae.

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

Eurypygiformes is an order formed by the kagus, comprising two species in the family Rhynochetidae endemic to New Caledonia, and the sunbittern from the tropical regions of the Americas. Its closest relatives appear to be the tropicbirds of the tropical Atlantic, Indian, and Pacific oceans.

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

Cariamiformes is an order of primarily flightless birds that has existed for over 50 million years. The group includes the family Cariamidae (seriemas) and the extinct families such as Phorusrhacidae, Bathornithidae, Idiornithidae and Ameghinornithidae. Extant members (seriemas) are only known from South America, but fossils of many extinct taxa are also found in other continents including Europe and North America. Though traditionally considered a suborder within Gruiformes, both morphological and genetic studies show that it belongs to a separate group of birds, Australaves, whose other living members are Falconidae, Psittaciformes and Passeriformes.

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

Messelasturidae is an extinct family of birds known from the Eocene of North America and Europe. Their morphology is a mosaic that in some aspects are very similar to modern hawks and falcons, but in others are more similar to parrots. Initially interpreted as stem-owls, more recent studies have suggested a closer relationship to parrots and passerines. Their ecology is enigmatic.

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

Halcyornithidae is an extinct family of telluravian birds thought to be related to the Psittaciformes (parrots), Passeriformes (songbirds), and to the extinct Messelasturidae. Halcyornithids have been found in various Eocene formations in Europe and North America. Widespread and diverse in the Early Eocene of North America and Europe, halcyornithids are not found in locales later than the Middle Eocene. Halcyornithids were small, arboreal birds with zygodactyl feet, with two toes facing forwards and two facing back, a trait shared with other tree-dwelling families of Eocene birds like the Zygodactylidae and the messelasturids. The skull of halcyornithids features a ridge of bone above the eye called the supraorbital process, similar to birds of prey. The relationships of the halcyornithids to other birds remain uncertain. Halcyornithids have been proposed as relatives to owls and as a lineage closer to parrots than to songbirds. Most recently, halcyornithids have been identified as the sister group of the clade including parrots and songbirds. It is also possible that Halcyornithidae is paraphyletic with respect to the Messelasturidae.

This is an overview of the paleofauna of the Eocene Messel Formation as explored by the Messel Pit excavations in Germany. A former quarry and now UNESCO World Heritage Site, the Messel Formation preserves what once were a series of anoxic lakes surrounded by a sub-tropical rainforest during the Middle Eocene, approximately 47 Ma.

Danielsraptor is an extinct genus of masillaraptorid bird from the Early Eocene (Ypresian) Walton Member of the London Clay Formation in Essex, United Kingdom. The genus contains a single species, D. phorusrhacoides, known from a partial skeleton.

<i>Ypresiglaux</i> Extinct genus of strigiform birds

Ypresiglaux is an extinct genus of strigiform bird from the Early Eocene London Clay Formation of Essex, United Kingdom and Nanjemoy Formation of Virginia, United States. The genus contains two species: Y. michaeldanielsi, known from a partial skeleton, and Y. gulottai, known from a distal tarsometatarsus.

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

Lutavis is an extinct genus of potentially afroavian bird from the Early Eocene London Clay Formation of Essex, United Kingdom. The genus contains a single species, L. platypelvis, known from a partial skeleton.

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

Waltonavis is an extinct genus of potentially leptosomiform bird from the Early Eocene London Clay Formation of Essex, United Kingdom. The genus contains two species: W. paraleptosomus and W. danielsi, both known from partial skeletons.

<i>Psittacomimus</i> Extinct genus of psittacopedid birds

Psittacomimus is an extinct genus of psittacopedid bird from the Early Eocene London Clay Formation of Essex, United Kingdom. The genus contains a single species, P. eos, known from a partial skeleton.

Halcyornis is an extinct genus of halcyornithid bird. It is known from a single neurocranium from the Early Eocene London Clay of southeastern England, and contains a single species, Halcyornis toliapicus. The type specimen of Halcyornis was the first fossil bird to be scientifically named.

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

Cyrilavis is an extinct genus of halcyornithid bird from the Early Eocene Fossil Butte Member of the Green River Formation, United States. The genus contains two species, Cyrilavis olsoni and Cyrilavis colburnorum.

Pulchrapollia is an extinct genus of halcyornithid bird from the Early Eocene London Clay of Walton-on-the-Naze, United Kingdom and the Nanjemoy Formation of Virginia, United States. The genus contains three species, Pulchrapollia gracilis, Pulchrapollia tenuipes and Pulchrapollia eximia.

References

  1. 1 2 3 4 5 6 Mayr, Gerald (2022), Mayr, Gerald (ed.), "Phaethontiformes and Aequornithes: The Aquatic and Semi-aquatic Neaovian Taxa", Paleogene Fossil Birds, Cham: Springer International Publishing, pp. 117–152, doi:10.1007/978-3-030-87645-6_7, ISBN   978-3-030-87645-6 , retrieved 2024-10-15
  2. 1 2 Mayr, Gerald; Kitchener, Andrew C. (2023-06-01). "Multiple skeletons of Rhynchaeites from the London Clay reveal the osteology of early Eocene ibises (Aves, Threskiornithidae)". PalZ. 97 (2): 425–442. doi: 10.1007/s12542-022-00647-1 . ISSN   1867-6812.
  3. Mayr, Gerald; Bertelli, Sara (2011-09-01). "A record of Rhynchaeites (Aves, Threskiornithidae) from the early Eocene Fur Formation of Denmark, and the affinities of the alleged parrot Mopsitta". Palaeobiodiversity and Palaeoenvironments. 91 (3): 229–236. doi:10.1007/s12549-011-0050-8. ISSN   1867-1608.