Cerebavis

Last updated

Cerebavis
Temporal range: Late Cretaceous, Cenomanian
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Avialae
Clade: Ornithurae
Genus: Cerebavis
Kurochkin et al., 2006
Species:
C. cenomanica
Binomial name
Cerebavis cenomanica
Kurochkin et al., 2006

Cerebavis (from Latin cerebrum, "brain", and avis, "bird") is an extinct genus of ornithurine dinosaurs that lived during the middle Cenomanian of the Late Cretaceous period, and is known from a single partial skull (PIN 5028/2) found in the Melovatskaya Formation of Volgograd Region in Russia. The skull was initially described as the fossilised brain of an enantiornithean by Russian palaeornithologist Evgeny Kurochkin and colleagues in 2006. Kurochkin and colleagues described Cerebavis as having a notable mixture of ancestral traits, such as a well-developed olfactory system, with derived traits of modern birds like a large cerebrum. At the same time, they identified various unusual and unique features not seen in the brains of reptiles or birds. These include well-developed auditory tubercles on the midbrain, as well as a prominent parietal organ compared to living birds or Archaeopteryx between them. [1]

In 2011 the fossil was reinterpreted as an incomplete and heavily abraded skull rather than a fossilised brain, and regarded Cerebavis as a probable non-enantiornithean bird and potentially a nomen dubium . [2] In 2015, a detailed reappraisal of the specimen by the same authors concluded that it belonged to an ornithurine instead of an enantiornithean and revised its diagnosis. Cerebavis was reidentified as an ornithurine as it seemingly lacked a postorbital bone and consequently a temporal bar dividing the temporal fenestra, as well as the thinness of the skull roof and the high degree of fusion between the bones of the skull. Despite not preserving the brain itself as was originally thought, the surface of the skull closely corresponded to the shape of the brain and its endocast (the internal shape of the braincase) was described. The brain more closely resembles that of living birds than originally interpreted by Kurochkin and colleagues, lacking a large pineal gland and with olfactory bulbs of expected size compared to living birds. Notably though, despite its advanced size and shape Cerebavis seemingly lacked a wulst, a structure found in the brains of modern birds, suggesting its brain was not fully modern. [3]

Related Research Articles

<span class="mw-page-title-main">Cerebrum</span> Large part of the brain containing the cerebral cortex

The cerebrum, telencephalon or endbrain is the largest part of the brain containing the cerebral cortex, as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system. The cerebrum develops prenatally from the forebrain (prosencephalon). In mammals, the dorsal telencephalon, or pallium, develops into the cerebral cortex, and the ventral telencephalon, or subpallium, becomes the basal ganglia. The cerebrum is also divided into approximately symmetric left and right cerebral hemispheres.

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

Confuciusornis is a genus of basal crow-sized avialan from the Early Cretaceous Period of the Yixian and Jiufotang Formations of China, dating from 125 to 120 million years ago. Like modern birds, Confuciusornis had a toothless beak, but closer and later relatives of modern birds such as Hesperornis and Ichthyornis were toothed, indicating that the loss of teeth occurred convergently in Confuciusornis and living birds. It was thought to be the oldest known bird to have a beak, though this title now belongs to an earlier relative Eoconfuciusornis. It was named after the Chinese moral philosopher Confucius. Confuciusornis is one of the most abundant vertebrates found in the Yixian Formation, and several hundred complete specimens have been found.

<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.

<i>Deinocheirus</i> Genus of theropod dinosaurs

Deinocheirus is a genus of large ornithomimosaur that lived during the Late Cretaceous around 70 million years ago. In 1965, a pair of large arms, shoulder girdles, and a few other bones of a new dinosaur were first discovered in the Nemegt Formation of Mongolia. In 1970, this specimen became the holotype of the only species within the genus, Deinocheirus mirificus; the genus name is Greek for "horrible hand". No further remains were discovered for almost fifty years, and its nature remained a mystery. Two more complete specimens were described in 2014, which shed light on many aspects of the animal. Parts of these new specimens had been looted from Mongolia some years before, but were repatriated in 2014.

<i>Garudimimus</i> Ornithomimosaur genus from the Late Cretaceous

Garudimimus is a genus of ornithomimosaur that lived in Asia during the Late Cretaceous. The genus is known from a single specimen found in 1981 by a Soviet-Mongolian paleontological expedition in the Bayan Shireh Formation and formally described in the same year by Rinchen Barsbold; the only species is Garudimimus brevipes. Several interpretations about the anatomical traits of Garudimimus were made in posterior examinations of the specimen, but most of them were criticized during its comprehensive redescription in 2005. Extensive undescribed ornithomimosaur remains at the type locality of Garudimimus may represent additional specimens of the genus.

Bissektipelta is a genus of ankylosaurine thyreophoran dinosaurs that lived in Asia during the Late Cretaceous in what is now the Bissekty Formation of Uzbekistan. Bissektipelta is a monospecific genus, containing only the type species B. archibaldi.

<i>Erlikosaurus</i> Extinct genus of therizinosaurid dinosaur from the Late Cretaceous

Erlikosaurus is a genus of therizinosaurid that lived in Asia during the Late Cretaceous period. The fossils, a skull and some post-cranial fragments, were found in the Bayan Shireh Formation of Mongolia in 1972, dating to around 96 million and 89 million years ago. These remains were later described by Altangerel Perle and Rinchen Barsbold in 1980, naming the new genus and species Erlikosaurus andrewsi. It represents the second therizinosaur taxon from this formation with the most complete skull among members of this peculiar family of dinosaurs.

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

Gobipteryx is a genus of prehistoric bird from the Campanian Age of the Late Cretaceous Period. It is not known to have any direct descendants. Like the rest of the enantiornithes clade, Gobipteryx is thought to have gone extinct near the end of the Cretaceous.

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

Ichthyornithes is an extinct group of toothed avialan dinosaurs very closely related to the common ancestor of all modern birds. They are known from fossil remains found throughout the late Cretaceous period of North America, though only two genera, Ichthyornis and Janavis, are represented by complete enough fossils to have been named. Ichthyornitheans became extinct at the Cretaceous–Paleogene boundary, along with enantiornitheans, all other non-avian dinosaurs, and many other animal and plant groups.

Nanantius is a genus of extinct enantiornithean avialan known from the Early Cretaceous of Australia.

<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.

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

Sinornis is a genus of enantiornithean birds from the Lower Cretaceous Jiufotang Formation of the People's Republic of China.

<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>Nigersaurus</i> Genus of reptiles (fossil)

Nigersaurus is a genus of rebbachisaurid sauropod dinosaur that lived during the middle Cretaceous period, about 115 to 105 million years ago. It was discovered in the Elrhaz Formation in an area called Gadoufaoua, in Niger. Fossils of this dinosaur were first described in 1976, but it was only named Nigersaurus taqueti in 1999, after further and more complete remains were found and described. The genus name means "Niger reptile", and the specific name honours the palaeontologist Philippe Taquet, who discovered the first remains.

<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.

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

Ankylopollexia is an extinct clade of ornithischian dinosaurs that lived from the Late Jurassic to the Late Cretaceous. It is a derived clade of iguanodontian ornithopods and contains the subgroup Styracosterna. The name stems from the Greek word, “ankylos”, mistakenly taken to mean stiff, fused, and the Latin word, “pollex”, meaning thumb. Originally described in 1986 by Sereno, a most likely synapomorphic feature of a conical thumb spine defines the clade.

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

Bohaiornithidae is a group of early predatory enantiornithean dinosaurs from the early Cretaceous Period of China. All known specimens come from the Jiufotang Formation and Yixian Formation, dating to the early Aptian age, 125–120 million years ago. Bohaiornithidae was first coined by Wang and colleagues in 2014. They defined it as the natural group formed by all descendants of the common ancestor of the type species, Bohaiornis guoi, and Shenqiornis mengi.

<i>Longusunguis</i> Extinct genus of dinosaurs

Longusunguis is an extinct genus of bohaiornithid enantiornithean dinosaur known from the Early Cretaceous of Liaoning Province, northeastern China. It contains a single species, Longusunguis kurochkini.

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

Cruralispennia is an extinct genus of enantiornithean bird. The only known specimen of Cruralispennia was discovered in the Early Cretaceous Huajiying Formation of China and formally described in 2017. The type species of Cruralispennia is Cruralispennia multidonta. The generic name is Latin for "shin feather", while the specific name means "many-toothed". The holotype of Cruralispennia is IVPP 21711, a semi-articulated partial skeleton surrounded by the remains of carbonized feathers.

<i>Asteriornis</i> Fossil bird genus from Belgium

Asteriornis is an extinct genus of bird from the Late Cretaceous of Belgium which is known from a single species, Asteriornis maastrichtensis. It was closely related to birds of the extant superorder Galloanserae such as chickens and ducks. Members of the genus were small, long-legged birds that lived near the coastline and co-existed with more "primitive" types of birds such as Ichthyornis. Asteriornis is one of the oldest-known birds irrefutably belonging to the group Neornithes, which encompasses all modern birds. It possesses characteristics of both galliformes and anseriformes, indicating its position as a close relative of the last common ancestor for both groups.

References

  1. Kurochkin, E. N.; Saveliev, S. V.; Postnov, A. A.; Pervushov, E. M.; Popov, E. V. (2006). "On the brain of a primitive bird from the Upper Cretaceous of European Russia". Paleontological Journal. 40 (6): 655–667. doi:10.1134/s0031030106060086.
  2. Walsh, S. A.; Milne, A. C. (2011). "Evolution of the avian brain and senses". In Dyke, G.; Kaiser, G. (eds.). Living Dinosaurs: The Evolutionary History of Modern Birds. Chichester: John Wiley & Sons. pp. 282–305. doi:10.1002/9781119990475.ch11. ISBN   9780470656662.
  3. Walsh, S A.; Milner, A. C.; Bourdon, E. (2016). "A reappraisal of Cerebavis cenomanica (Aves, Ornithurae), from Melovatka, Russia". Journal of Anatomy. 229 (2): 215–227. doi:10.1111/joa.12406. PMC   4948046 . PMID   26553244.