Morsoravis

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Morsoravis
Temporal range: Early Eocene
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Family: Morsoravidae
Genus: Morsoravis
Bertelli et al., 2010
Species:
M. sedilis
Binomial name
Morsoravis sedilis
(Bertelli et al. 2010)

Morsoravis is an extinct genus of neoavian bird from the Early Eocene Fur Formation of Denmark. It contains a single named species, Morsoravis sedilis. Fossils of Morsoravis have also been found in the Green River Formation of Wyoming and possibly the Nanjemoy Formation of Virginia.

Contents

Discovery and naming

The holotype of Morsoravis, MGUH 28930, consists of an complete but fully articulated and three-dimensionally preserved skeleton, found in the marine Fur Formation of Denmark. There are several fish bones preserved within the body of the bird, although there are also other fish fossils surrounding the specimen. The fossil was collected from a site on the northwestern corner of the island of Mors, at the base of a cliff. [1]

Although Morsoravis belongs to its own family, Morsoravidae, and is related to the Psittacopedidae, [2] it was first formally described as a relative of the Charadriiformes by Bertelli et al. in 2010. Before that, it had been the subject of research in two unpublished doctoral theses in 2002 and 2007. [3] Additionally, it had been inadequately described as a nomen nudum under the name "Morsoravis sedile" [1] in Dyke & Tuinen (2004). [4]

The generic name Morsoravis comes from Mors, the name of the island on which the holotype was collected, Latin sor, meaning "shore", and avis, meaning bird. The specific ephitet, sedilis, is from Latin "sedere", meaining to sit still, and ilis, expressing capability, referencing Morsoravis' capability to perch. [1]

A fossil from the Green River Formation in Wyoming belongs to an unnamed species of Morsoravis, and preserves the forelimbs, unlike the holotype. [5] Remains of Morsoravis-like bone fragments have been found from the Nanjemoy Formation of Virginia, United States. However, the fragmentary nature of these specimens prohibits confident assignment to the genus. [6] A further specimen from the Fur Formation, preserving elements of the wing and pectoral area not found in the holotype, belongs to Morsoravis, but it is now lost. [7]

Description

Morsoravis had a rounded head totalling about 31.8 mm (1.25 in), of which about half is accounted for by the relatively long beak, with a rounded braincase. The beak is straight and pointed at its tip, and has an elongated nostril. The beak is schizorhinal, suggesting the possibility of rhynchokinetism of the rostrum. The orbit is about the size of the braincase, and the sclerotic ring is made of 12 segments. The interorbital septum, the bone between the two orbits, has a single fenestra. There is either a very weakly developed basipterygoid process or none at all. The skull of the holotype preserves many details of the inner ear and surrounding area well. [1]

In Morsoravis there are 21 presacral vertebrae, that is, vertebrae cranial of the synsacrum, which exhibit a pleurocoelous condition. [3] There are 11 synsacral vertebrae and a further 7 caudal vertebrae. The pygostyle is large. The pelvis is incompletely fused to the synsacrum, which is true of adult Morsoravis. [1]

The tarsometatarsus is highly similar to that of Pumiliornis , a psittacopedid bird, and features an accessary trochlea of the trochlea of the fourth metatarsal, indicative of at least semi-zygodactyly. The hallux is relatively long and has a large, curved claw, and the proportions of the toes are not characteristic of ground-dwelling birds. [1] The semi-zygodactyl foot also has a second toe with relatively little freedom of side-to-side motion, likely an adaptation for climbing. [2]

Classification

The history of the classification of Morsoravis is convoluted. Dyke & van Tuinen (2004) [4] figured the holotype of Morsoravis and classified it as a charadriiform bird, but provided no formal description, making their name, "Morsoravis sedile", a nomen nudum. The first formal description of the bird, by Bertelli et al., agreed with this assessment, partially due to details of the vertebrae. Mayr (2011) [3] classified the bird together with Pumiliornis, and Mayr (2015) [8] included Morsoravis in the new family Psittacopedidae. With new fossil evidence from the new genus Sororavis, Mayr (2023) described a new family, Morsoravidae, with Morsoravis as the type genus, and including Pumiliornis and Sororavis, to the exclusion of the other birds previously described as psittacopedids.

Related Research Articles

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

Charadriiformes is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water and eat invertebrates or other small animals; however, some are pelagic (seabirds), others frequent deserts, and a few are found in dense forest. Members of this group can also collectively be referred to as shorebirds.

<span class="mw-page-title-main">Fur Formation</span> Marine geologial formation in Denmark

The Fur Formation is a marine geological formation of Ypresian age which crops out in the Limfjord region of northern Denmark from Silstrup via Mors and Fur to Ertebølle, and can be seen in many cliffs and quarries in the area. The Diatomite Cliffs is on the Danish list of tentative candidates for World Heritage and may become a World Heritage site. Fossils found in the Fur Formation are primarily housed at the Fossil and Mo-clay Museum on Mors Island, the Fur Museum on Fur Island, and the Natural History Museum of Denmark in Copenhagen.

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

Kelenken is a genus of phorusrhacid, an extinct group of large, predatory birds, which lived in what is now Argentina in the middle Miocene about 15 million years ago. The only known specimen was discovered by high school student Guillermo Aguirre-Zabala in Comallo, in the region of Patagonia, and was made the holotype of the new genus and species Kelenken guillermoi in 2007. The genus name references a spirit in Tehuelche mythology, and the specific name honors the discoverer. The holotype consists of one of the most complete skulls known of a large phorusrhacid, as well as a tarsometatarsus lower leg bone and a phalanx toe bone. The discovery of Kelenken clarified the anatomy of large phorusrhacids, as these were previously much less well known. The closest living relatives of the phorusrhacids are the seriemas. Kelenken was found to belong in the subfamily Phorusrhacinae, along with for example Devincenzia.

<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.

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.

Eostrix is a genus of extinct primitive owls in the family Protostrigidae, along with Oligostrix and Minerva. These owls date from the early Eocene of the United States, Europe, and Mongolia. They have been described based on fossil remains. The genus was created by Pierce Brodkorb in 1971 to place a fossil species known until that time as Protostrix mimica.

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

Juncitarsus is an extinct genus of wading birds from the Eocene of the United States and Germany. Though previously considered a flamingo, it is likely a stem-flamingo, possibly a relative of the group which contains both flamingos and grebes (Mirandornithes).

<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.

Vastanavidae is an extinct family of birds related to parrots and passerine birds. They are known from fossils from Eocene sites in India, Europe, and North America. The vastanavids resemble parrots and the extinct parrot relative Quercypsitta in their morphology, including the partially zygodactyl foot, in which two toes could face opposite the other two.

<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.

Protostrigidae is a prehistoric family of owls which occurred in North America, Europe, and Asia during the Eocene and early Oligocene periods. Genera include Eostrix, Minerva, Oligostrix, and Primoptynx. In 1983, Cécile Mourer-Chauviré demonstrated that Protostrix is a junior synonym of Minerva.

Scandiavis is genus of prehistoric birds related to Charadriiformes. It is known from the Fur Formation of Denmark.

<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.

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.

Parapsittacopes is an extinct genus of psittacopedid bird from the Early Eocene London Clay, United Kingdom. The genus contains one species, Parapsittacopes bergdahli.

Eofringillirostrum is an extinct species of bird known from the Early Eocene Green River Formation of the Western United States and from the Messel Pit in Germany. The genus contains two species, Eofringillirostrum boudreauxi and Eofringillirostrum parvulum. They are the earliest known fossil birds to have a finch-like beak.

Sororavis is an extinct genus of bird from the Early Eocene London Clay of Walton-on-the-Naze, United Kingdom. It contains a single named species, Sororavis solitarius. It is a member of the Morsoravidae.

Morsoravidae is a family of extinct birds known from the Early Eocene of Europe and North America, related to the Psittacopasseres, the clade containing parrots and songbirds. They have specialised feeding ecologies, and one morsoravid, Pumiliornis tesselatus, fed on nectar. The family contains the genera Morsoravis, Pumiliornis, and Sororavis.

References


  1. 1 2 3 4 5 6 Bertelli, Sara; Lindow, Bent E. K.; Dyke, Gareth J.; Chiappe, Luis M. (2009-01-09). "A well-preserved 'charadriiform-like' fossil bird from the Early Eocene Fur Formation of Denmark: 'CHARADRIIFORM-LIKE' FOSSIL BIRD FROM THE FUR FORMATION". Palaeontology. 53 (3): 507–531. doi: 10.1111/j.1475-4983.2010.00950.x .
  2. 1 2 "A new fossil from the London Clay documents the convergent origin of a "mousebird-like" tarsometatarsus in an early Eocene near-passerine bird - Acta Palaeontologica Polonica". www.app.pan.pl. Retrieved 2023-11-04.
  3. 1 2 3 "Bulletin Volume 59 – 2011". Dansk Geologisk Forening (in Danish). 2011-05-24. doi:10.37570/bgsd-2011-59-03 . Retrieved 2023-11-04.
  4. 1 2 Dyke, Gareth J.; Van Tuinen, Marcel (2004-06-10). "The evolutionary radiation of modern birds (Neornithes): reconciling molecules, morphology and the fossil record". Zoological Journal of the Linnean Society. 141 (2): 153–177. doi: 10.1111/j.1096-3642.2004.00118.x . ISSN   1096-3642.
  5. Ksepka, Daniel T.; Grande, Lance; Mayr, Gerald (2019-02-18). "Oldest Finch-Beaked Birds Reveal Parallel Ecological Radiations in the Earliest Evolution of Passerines". Current Biology. 29 (4): 657–663.e1. doi: 10.1016/j.cub.2018.12.040 . ISSN   0960-9822.
  6. Mayr, Gerald; De Pietri, Vanesa; Paul Scofield, R. (2022-02-01). "New bird remains from the early Eocene Nanjemoy Formation of Virginia (USA), including the first records of the Messelasturidae, Psittacopedidae, and Zygodactylidae from the Fisher/Sullivan site". Historical Biology. 34 (2): 322–334. doi: 10.1080/08912963.2021.1910820 . ISSN   0891-2963.
  7. Mayr, Gerald (2022). Paleogene fossil birds. Fascinating life sciences (2nd ed.). Cham: Springer. ISBN   978-3-030-87644-9.
  8. Mayr, Gerald (2015-06-25). "A reassessment of E ocene parrotlike fossils indicates a previously undetected radiation of zygodactyl stem group representatives of passerines ( P asseriformes)". Zoologica Scripta. 44 (6): 587–602. doi:10.1111/zsc.12128. ISSN   0300-3256.