Avisaurus

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Avisaurus
Temporal range: Late Cretaceous
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Avisaurus.jpg
Holotype tarsometatarsus
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Avialae
Clade: Enantiornithes
Family: Avisauridae
Genus: Avisaurus
Brett-Surman & Paul, 1985
Type species
Avisaurus archibaldi
Brett-Surman & Paul, 1985
Species
  • A. archibaldiBrett-Surman and Paul, 1985

Avisaurus (meaning "bird lizard") is a genus of enantiornithine bird from the Late Cretaceous of North America. [1]

Contents

Discovery

Avisaurus archibaldi was discovered in the Late Cretaceous Hell Creek Formation of North America (Maastrichtian, from c.70.6-66 million years ago), making it one of the last enantiornithids. It was collected in 1975 in the UCMP locality V73097, in Garfield County, Montana, USA. The holotype is represented by a single fossil of a tarsometatarsus in the collection of the University of California Museum of Paleontology. It has the catalog number UCMP 117600. The species name honors J. David Archibald, its discoverer, from The University of California, Berkeley. It was initially described as the left tarsometatarsus of a non-avian theropod by Brett-Surman and Paul in 1985. It was later redescribed as the right tarsometatarsus of an enantiornithine bird by Chiappe in 1992. [2]

Avisaurus gloriae Varricchio and Chiappe 1995, [3] discovered in the late Campanian Upper Two Medicine Formation of Glacier County, Montana, USA, was renamed Gettyia by Atterholt et al. (2018). [4]

Description

Size (lower right) compared to contemporary birds, pterosaurs, and a human Pterosauria journal.pbio.2001663.g020.png
Size (lower right) compared to contemporary birds, pterosaurs, and a human

The specimen has a maximum length of 73.9 mm (2.91 in), making it one of the largest known tarsometatarsi of an enantiornithine. [3] RAM 14306, an incomplete coracoid, is bigger than the holotype. It indicates an animal with a length of 72 cm (28 in), hip height of 31.5 cm (12.4 in), and weight of 5.1 kg (11 lb). [5]

Classification

This genus belongs to the enantiornithine family Avisauridae, which also contains similar animals from South America such as Soroavisaurus [6] and Neuquenornis [7] In the Late Cretaceous the Americas were still separated by a branch of the Tethys Ocean.

The paper by Brett-Surman and Paul in 1985 explicitly considered the possibility that A. archibaldi was an enantiornithine. The authors described and named UCMP 117600 formally, but they looked at other enantiornithine material, including the "metatarsus" PVL 4690 from Argentina. The authors assigned this latter fossil to Avisaurus sp. From this they concluded that members of the genus Avisaurus existed in both North and South America in the Late Cretaceous. Moreover, the authors concluded that the length/width ratio and degree of metacarpal fusion of these bones were more like those of non — avian dinosaurs. A terrestrial dinosaur genus in both continents would then support Brett — Surman's theory that there had been a land connection between the two continents. [8]

Further discoveries and further study by Chiappe showed that all of the material belonged to enantiornithine birds, and PVL 4690 was given its own genus Soroavisaurus . [2]

Paleoenvironment

Restoration of Avisaurus and Brachychampsa Avisaurus and Brachychampsa by tomozsaurus.jpg
Restoration of Avisaurus and Brachychampsa

Avisaurus remains fossilized in the humid low-lying swamps, lakes, and river basins of the western shore of the Western Interior Seaway, Hell Creek Formation. Some remains also preserved from the much more arid uplands between that area and the Cordilleran Overthrust Belt which eventually formed the Rocky Mountains [ citation needed ].

Paleobiology

Inwardly curved claws of the Avisaurus tarsis resemble those of eudromaeosaurs, indicating that it was predatory. It likely preyed on other vertebrates, with similarity to some modern raptors. [9]

Related Research Articles

<span class="mw-page-title-main">Gregory S. Paul</span> American researcher, author and illustrator

Gregory Scott Paul is an American freelance researcher, author and illustrator who works in paleontology. He is best known for his work and research on theropod dinosaurs and his detailed illustrations, both live and skeletal. Professionally investigating and restoring dinosaurs for three decades, Paul received an on-screen credit as dinosaur specialist on Jurassic Park and Discovery Channel's When Dinosaurs Roamed America and Dinosaur Planet. He is the author and illustrator of Predatory Dinosaurs of the World (1988), The Complete Illustrated Guide to Dinosaur Skeletons (1996), Dinosaurs of the Air (2001), The Princeton Field Guide to Dinosaurs (2010), Gregory S. Paul's Dinosaur Coffee Table Book (2010), The Princeton Field Guide to Dinosaurs: 2nd Edition (2016), The Princeton Field Guide to Pterosaurs (2022), The Princeton Field Guide to Mesozoic Sea Reptiles (2022) and editor of The Scientific American Book of Dinosaurs (2000).

<span class="mw-page-title-main">Enantiornithes</span> Extinct clade of dinosaurs

The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans, the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over eighty species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs.

<span class="mw-page-title-main">Anacleto Formation</span> Geologic formation in Argentina

The Anacleto Formation is a geologic formation with outcrops in the Argentine Patagonian provinces of Mendoza, Río Negro, and Neuquén. It is the youngest formation within the Neuquén Group and belongs to the Río Colorado Subgroup. Formerly that subgroup was treated as a formation, and the Anacleto Formation was known as the Anacleto Member.

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

Yungavolucris is a genus of enantiornithean birds. It contains the single species Yungavolucris brevipedalis, which lived in the Late Cretaceous. The fossil bones were found in the Lecho Formation at estancia El Brete, Argentina."Yungavolucris brevipedalis" means "Short-footed Yungas bird". The generic name, Yungavolucris is after the Yungas region + the Latin volucris, which translates to "bird". The specific name brevipedalis is from the Latin brevis, which means "short", + pedalis, from the Latin pes, meaning "foot".

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

Lectavis is a genus of enantiornithine birds. Their fossil bones have been recovered from the Late Cretaceous Lecho Formation at estancia El Brete, Argentina. The genus contains a single species, Lectavis bretincola.

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

Eoalulavis is a monotypic genus of enantiornithean bird that lived during the Barremian, in the Lower Cretaceous around 125 million years ago. The only known species is Eoalulavis hoyasi.

Elsornis is a genus of enantiornithine bird. Only one species is known, Elsornis keni. It lived during the Late Cretaceous. It is known from a partially articulated fossil skeleton found in the Gobi Desert in Mongolia.

Neuquenornis volans is a species of enantiornithean birds which lived during the late Cretaceous period in today's Patagonia, Argentina. It is the only known species of the genus Neuquenornis. Its fossils were found in the Santonian Bajo de la Carpa Formation, dating from about 85-83 million years ago. This was a sizeable bird for its time, with a tarsometatarsus 46.8mm long. Informal estimates suggest that it measured nearly 30 cm (12 in) in length excluding the tail.

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 1993.

<span class="mw-page-title-main">Pygostylia</span> Clade of dinosaurs

Pygostylia is a group of avialans which includes the Confuciusornithidae and all of the more advanced species, the Ornithothoraces.

<span class="mw-page-title-main">Avisauridae</span> Extinct family of dinosaurs

Avisauridae is a family of extinct enantiornithine dinosaurs from the Cretaceous period, distinguished by several features of their ankle bones. Depending on the definition used, Avisauridae is either a broad and widespread group of advanced enantiornithines, or a small family within that group, restricted to species from the Late Cretaceous of North and South America.

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

Shanweiniao is a genus of long-snouted enantiornithean birds from Early Cretaceous China. One species is known, Shanweiniao cooperorum. There is one known fossil, a slab and counterslab. The fossil is in the collection of the Dalian Natural History Museum, and has accession number DNHM D1878/1 and DNHM1878/2. It was collected from the Lower Cretaceous Dawangzhengzi Beds, middle Yixian Formation, from Lingyuan in the Liaoning Province, China.

Soroavisaurus is a genus of enantiornithean birds related to Avisaurus. It lived during the Late Cretaceous of Argentina. The only known species, S. australis, is known from fossils collected from the Lecho Formation of Estancia El Brete, in the southern tip of the province of Salta, Argentina. A binominal name of this animal means "Southern sister Avisaur".

<span class="mw-page-title-main">Longipterygidae</span> Extinct family of dinosaurs

Longipterygidae is a family of early enantiornithean avialans from the Early Cretaceous epoch of China. All known specimens come from the Jiufotang Formation and Yixian Formation, dating to the early Aptian age, 125-120 million years ago.

Martinavis is a genus of enantiornithine birds which existed in what is now southern France, North America and Salta Province, Argentina during the late Cretaceous period. It was named by Cyril A. Walker, Eric Buffetaut and Gareth J. Dyke in 2007, and the type species is Martinavis cruzyensis.

<span class="mw-page-title-main">Luis M. Chiappe</span> Argentine paleontologist (born 1962)

Luis María Chiappe is an Argentine paleontologist born in Buenos Aires who is best known for his discovery of the first sauropod nesting sites in the badlands of Patagonia in 1997 and for his work on the origin and early evolution of Mesozoic birds. He is currently the Vice President of Research and Collections at the Natural History Museum of Los Angeles County and director of the museum's Dinosaur Institute. He was a postdoctoral researcher at the American Museum of Natural History, New York after immigrating from Argentina. Chiappe is currently the curator of the award winning Dinosaur Hall at the Natural History Museum of Los Angeles County, an adjunct professor at the University of Southern California, BBC advisor and author of scientific and popular books.

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

Mirarce is a genus of enantornithe bird from the Late Cretaceous of Utah. It contains a single species, M. eatoni. It was similar in size to modern turkeys.

Gettyia is an extinct genus of avisaurid enantiornithean bird from the Late Cretaceous of North America.

<span class="mw-page-title-main">Jingmai O'Connor</span> American paleontologist

Jingmai Kathleen O'Connor is a paleontologist who works as a curator at the Field Museum.

References

  1. PaleoBiology Database: Avisaurus, basic info
  2. 1 2 Chiappe, Luis M. (1992) "Enantiornithine (Aves) Tarsometatarsi and the Avian Affinities of the Late Cretaceous Avisauridae" "Journal of Vertebrate Paleontology" September 3, 1992, Volume 12 no. 3 pp. 344-350
  3. 1 2 Varricchio, David J., Chiappe, Luis M. (1995) "A New Enantiornithine Bird From the Upper Cretaceous Two medicine Formation of Montana" " Journal of Vertebrate Paleontology" March 14, 1995, Vol. 15, no. 1, pp. 201 - 204
  4. Atterholt J, Hutchison JH, O’Connor JK. (2018) The most complete enantiornithine from North America and a phylogenetic analysis of the Avisauridae. PeerJ 6:e5910 https://doi.org/10.7717/peerj.5910
  5. Rubén Molina-Pérez, Asier Larramendi, David Connolly, Gonzalo Ángel Ramírez Cruz, Andrey Atuchin (June 25, 2019). Dinosaur Facts and Figures: The Theropods and Other Dinosauriformes. Princeton University Press. p. 281. ISBN   9780691190594 . Retrieved 29 August 2022.{{cite book}}: CS1 maint: multiple names: authors list (link)
  6. Chiappe, Luis M. (1993) " Enantiornithine (Aves) Tarsometatarsi from the Cretaceous Lecho Formation of Northwestern Argentina" American Museum Novitates December 27, 1993 Number 3083 pp. 1-2
  7. Chiappe, Luis M., Calvo, Jorge O. (1994) "Neuquenornis volans, a New Late Cretaceous Bird (Enantiornithes: Avisauridae) from Patagonia, Argentina" "Journal of Vertebrate Paleontology" June 22, 1994 Volume 14 No. 2 pp.230-246.
  8. Brett-Surman, Michael K., Paul, Gregory S. (1985) "A new family of bird-like dinosaurs linking Laurasia and Gondwanaland." "Journal of Vertebrate Paleontology" 5(2): 133-138.
  9. Matthew P. Martyniuk (2012). A Field Guide to Mesozoic Birds and Other Winged Dinosaurs. Pan Aves. p. 142. ISBN   9780988596504 . Retrieved 29 August 2022.

Further reading