Maniraptora

Last updated

Maniraptorans
Temporal range:
Middle Jurassic–Present, 165–0  Ma [1]
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
Possible Early Jurassic record [2]
Maniraptora Infobox Panoply.png
Collage of six maniraptorans. From top left to right: the Zamyn Khondt oviraptorid, Sinornithosaurus , the Prince Creek troodontid, Patagonykus , a short-tailed albatross, and Nothronychus
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Maniraptoriformes
Clade: Maniraptora
Gauthier, 1986
Subgroups
Synonyms
  • MetornithesPerle et al., 1993

Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the non-avian dinosaurs that were more closely related to them than to Ornithomimus velox . It contains the major subgroups Avialae, Dromaeosauridae, Troodontidae, Oviraptorosauria, and Therizinosauria. Ornitholestes and the Alvarezsauroidea are also often included. Together with the next closest sister group, the Ornithomimosauria, Maniraptora comprises the more inclusive clade Maniraptoriformes. Maniraptorans first appear in the fossil record during the Jurassic Period (see Eshanosaurus ), and survive today as living birds.

Contents

Description

Microraptor specimen with feather impressions MicroraptorGui-PaleozoologicalMuseumOfChina-May23-08.jpg
Microraptor specimen with feather impressions

Maniraptorans are characterized by long arms and three-fingered hands (though reduced or fused in some lineages), as well as a "half-moon shaped" (semi-lunate) bone in the wrist (carpus). In 2004, Tom Holtz and Halszka Osmólska pointed out six other maniraptoran characters relating to specific details of the skeleton. Unlike most other saurischian dinosaurs, which have pubic bones that point forward, several groups of maniraptorans have an ornithischian-like backwards-pointing hip bone. A backward-pointing hip characterizes the therizinosaurs, dromaeosaurids, avialans, and some primitive troodontids. The fact that the backward-pointing hip is present in so many diverse maniraptoran groups has led most scientists to conclude that the "primitive" forward-pointing hip seen in advanced troodontids and oviraptorosaurs is an evolutionary reversal, and that these groups evolved from ancestors with backward-pointing hips. [3]

Technical diagnosis

Holtz and Osmólska (2004) diagnosed the clade Maniraptora based on the following characters: reduced or absent olecranon process of the ulna, greater trochanter and cranial trochanter of the femur fused into a trochanteric crest. An elongated, backwards-pointing pubic bone is present in therizinosauroids, dromaeosaurids, avialans, and the basal troodontid Sinovenator , which suggests that the propubic condition in advanced troodontids and oviraptorosaurs is a reversal. [3] Turner et al. (2007) named seven synapomorphies that diagnose Maniraptora. [4]

Feathers and flight

Canada goose flying Branta canadensis -near Oceanville, New Jersey, USA -flying-8.jpg
Canada goose flying

Modern pennaceous feathers and remiges are known in the advanced maniraptoran group Aviremigia. More primitive maniraptorans, such as therizinosaurs (specifically Beipiaosaurus ), preserve a combination of simple downy filaments and unique elongated quills. [5] [6] Simple feathers are known from more primitive coelurosaurs such as Sinosauropteryx prima , and possibly from even more distantly related species such as the ornithischian Tianyulong confuciusi and the flying pterosaurs. Thus it appears as if some form of feathers or down-like integument would have been present in all maniraptorans, at least when they were young. [4]

Maniraptora is the only dinosaur group known to include flying members, though how far back in this lineage flight extends is controversial. Powered and/or gliding flight is believed to have been present in some types of non-avialan paravians, including dromaeosaurids, such as Rahonavis and Microraptor . [7] Zhenyuanlong suni , a dromaeosaurid, was too heavy to fly but still had wings with feathers required for flying, which suggests its ancestors had the ability for aerial locomotion. [8] Other groups, like the Oviraptorosauria who had a tail with a tail fan of feathers with caudal anatomy resembling a pygostyle, are not known to have been capable of flight, but some scientists, such as Gregory S. Paul, have suggested that they could be descended from ancestors which flew. Paul has gone as far as to propose that Therizinosauria, Alvarezsauroidea, and the non-maniraptoran group Ornithomimosauria also descended from flying ancestors. [9]

Classification

The Maniraptora was originally named by Jacques Gauthier in 1986, for a branch-based clade defined as all dinosaurs closer to modern birds than to the ornithomimids. Gauthier noted that this group could be easily characterized by their long forelimbs and hands, which he interpreted as adaptations for grasping (hence the name Maniraptora, which means "hand snatchers" in relation to their 'seizing hands'). In 1994, Thomas R. Holtz attempted to define the group based on the characteristics of the hand and wrist alone (an apomorphy-based definition), and included the long, thin fingers, bowed, wing-like forearm bones, and half-moon shaped wrist bone as key characters. Most subsequent studies have not followed this definition, however, preferring the earlier branch-based definition.

The branch-based definition usually includes the major groups Dromaeosauridae, Troodontidae, Oviraptorosauria, Therizinosauria, and Avialae. [10] Other taxa often found to be maniraptorans include the alvarezsaurs and Ornitholestes . [4] [11] Several taxa have been assigned to the Maniraptora more definitively, though their exact placement within the group remains uncertain. These forms include the scansoriopterygids, Pedopenna , and Yixianosaurus .

In 1993, Perle and colleagues coined the name Metornithes to include alvarezsaurids and modern birds, which the researchers believed were members of the Avialae. This group was defined as a clade by Luis Chiappe in 1995 as the last common ancestor of Mononykus and modern birds, and all its descendants. [12]

Pennaraptora (Latin penna "bird feather" + raptor "thief", from rapere "snatch"; a feathered bird-like predator) is a clade within Maniraptora, defined as the most recent common ancestor of Oviraptor philoceratops , Deinonychus antirrhopus , and Passer domesticus (the house sparrow), and all descendants thereof, by Foth et al., 2014. [13]

The clade "Aviremigia" was conditionally proposed along with several other apomorphy-based clades relating to birds by Jacques Gauthier and Kevin de Queiroz in a 2001 paper. Their proposed definition for the group was "the clade stemming from the first panavian with ... remiges and rectrices, that is, enlarged, stiff-shafted, closed-vaned (= barbules bearing hooked distal pennulae), pennaceous feathers arising from the distal forelimbs and tail". [14] Ancestral morphology relating to pennaceous feathers suggests that basal species of Pennaraptora were capable of scansorial locomotion and gliding, and further evolution of said adaptation within the clade would eventually give rise to the origin of flight in avian species. [15]

The following cladogram follows the results of a phylogenetic study by Cau (2020). [16]

Maniraptora

Alternative interpretations

In 2002, Czerkas and Yuan reported that some maniraptoran traits, such as a long, backwards-pointed pubis and short ischia were present in Scansoriopteryx, a scansoriopterygid. The authors considered it to be more primitive than true theropods, and hypothesized that maniraptorans may have branched off from theropods at a very early point, or may even have descended from pre-theropod dinosaurs. [17] Zhang et al., in describing the closely related or conspecific specimen Epidendrosaurus (now considered a synonym of Scansoriopteryx ), did not report any of the primitive traits mentioned by Czerkas and Yuan, but did find that the shoulder blade of Epidendrosaurus appeared primitive. Despite this, they placed Epidendrosaurus firmly within Maniraptora due to a number of synapomorphies. [18]

Paleobiology

Diet

Jinfengopteryx elegans specimen with seeds preserved in the stomach region Jinfengopteryx elegans 2.JPG
Jinfengopteryx elegans specimen with seeds preserved in the stomach region

Scientists traditionally assumed that maniraptorans were ancestrally hypercarnivorous, that is, that most non-avialan species primarily ate and hunted only other vertebrates. However, a number of discoveries made during the first decade of the 21st century, as well as re-evaluation of older evidence, began to suggest that maniraptorans were a primarily omnivorous group, including a number of sub-groups that ate mainly plants, insects, or other food sources besides meat. Additionally, phylogenetic studies of maniraptoran relationships began to more consistently show that herbivorous or omnivorous groups were spread throughout the Maniraptora, rather than representing a single side-branch as previously thought. This led scientists such as Lindsay Zanno to conclude that the ancestral maniraptoran must have been omnivorous, giving rise to several purely herbivorous groups (such as the therizinosaurs, primitive oviraptorosaurs, and some avialans) and that, among non-avians, only one group reverted to pure carnivores (the dromaeosaurids). Most other groups fell somewhere in between the two extremes, with alvarezsaurids and some avialans being insectivorous, and with advanced oviraptorosaurs and troodontids being omnivorous. [10] [19] [20]

Reproduction

A 2023 study analyzing fossil eggshells assigned to Troodon with clumped isotope thermometry found that Troodon, and likely other non-avian maniraptorans, had a slowed calcification of eggs akin to that of most reptiles. This contrasts with the rapid calcification of eggs found in modern birds, indicating that most maniraptorans aside from birds retained this basal trait. This would also indicate that most non-avian maniraptorans possessed two functional ovaries, contrasting with the one functional ovary in birds, and were thus limited in the numbers of eggs each individual could produce. [21]

Related Research Articles

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

Theropoda, whose members are known as theropods, is an extant dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period 231.4 million years ago (Ma) and included the majority of large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous, about 66 Ma. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are today represented by about 11,000 living species.

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

Troodontidae is a clade of bird-like theropod dinosaurs from the Late Jurassic to Late Cretaceous. During most of the 20th century, troodontid fossils were few and incomplete and they have therefore been allied, at various times, with many dinosaurian lineages. More recent fossil discoveries of complete and articulated specimens, have helped to increase understanding about this group. Anatomical studies, particularly studies of the most primitive troodontids, like Sinovenator, demonstrate striking anatomical similarities with Archaeopteryx and primitive dromaeosaurids, and demonstrate that they are relatives comprising a clade called Paraves.

<span class="mw-page-title-main">Dromaeosauridae</span> Family of theropod dinosaurs

Dromaeosauridae is a family of feathered coelurosaurian theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek δρομαῖος (dromaîos), meaning 'running at full speed', 'swift', and σαῦρος (saûros), meaning 'lizard'. In informal usage, they are often called raptors, a term popularized by the film Jurassic Park; several genera include the term "raptor" directly in their name, and popular culture has come to emphasize their bird-like appearance and speculated bird-like behavior.

<i>Caudipteryx</i> Genus of oviraptorosaur dinosaurs

Caudipteryx is a genus of small oviraptorosaur dinosaurs that lived in Asia during the Early Cretaceous, around 124.6 million years ago. They were feathered and extremely birdlike in their overall appearance, to the point that some paleontologists suggested it was a bird. Two species have been described: C. zoui, in 1998, and C. dongi, in 2000.

<span class="mw-page-title-main">Alvarezsauridae</span> Family of extinct long-legged dinosaurs

Alvarezsauridae is a family of small, long-legged dinosaurs. Although originally thought to represent the earliest known flightless birds, they are now thought to be an early diverging branch of maniraptoran theropods. Alvarezsaurids were highly specialized. They had tiny but stout forelimbs, with compact, bird-like hands. Their skeletons suggest that they had massive breast and arm muscles, possibly adapted for digging or tearing. They had long, tube-shaped snouts filled with tiny teeth. They have been interpreted as myrmecophagous, adapted to prey on colonial insects such as termites, with the short arms acting as effective digging instruments to break into nests.

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

Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs.

<span class="mw-page-title-main">Oviraptorosauria</span> Extinct group of dinosaurs

Oviraptorosaurs are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, with or without bony crests atop the head. They ranged in size from Caudipteryx, which was the size of a turkey, to the 8-meter-long, 1.4-ton Gigantoraptor. The group is close to the ancestry of birds. Some researchers such as Maryanska et al (2002) and Osmólska et al. (2004) have proposed that they may represent primitive flightless birds. The most complete oviraptorosaur specimens have been found in Asia. The North American oviraptorosaur record is sparse.

<i>Jinfengopteryx</i> Theropod dinosaur genus

Jinfengopteryx is a genus of maniraptoran dinosaur. It was found in the Qiaotou Member of the Huajiying Formation of Hebei Province, China, and is therefore of uncertain age. The Qiaotou Member may correlate with the more well-known Early Cretaceous Yixian Formation, and so probably dates to around 122 Ma ago.

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

Yixianosaurus is a maniraptoran theropod dinosaur genus from the Early Cretaceous of China.

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

Scansoriopterygidae is an extinct family of climbing and gliding maniraptoran dinosaurs. Scansoriopterygids are known from five well-preserved fossils, representing four species, unearthed in the Tiaojishan Formation fossil beds of Liaoning and Hebei, China.

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

Incisivosaurus is a genus of small, probably herbivorous theropod dinosaurs from the early Cretaceous Period of what is now the People's Republic of China. The first specimen to be described, IVPP V13326, is a skull that was collected from the lowermost levels of the Yixian Formation in the Sihetun area, near Beipiao City, in western Liaoning Province. The most significant, and highly unusual, characteristic of this dinosaur is its apparent adaptation to an herbivorous or omnivorous lifestyle. It was named for its prominent, rodent-like front teeth, which show wear patterns commonly found in plant-eating dinosaurs. The specific name gauthieri honors Dr. Jacques Gauthier, a pioneer of the phylogenetic method of classification.

<span class="mw-page-title-main">Avialae</span> Clade including all birds and their ancestors

Avialae is a clade containing the only living dinosaurs, the birds, and their closest relatives. It is usually defined as all theropod dinosaurs more closely related to birds (Aves) than to deinonychosaurs, though alternative definitions are occasionally used.

<span class="mw-page-title-main">Paraves</span> Clade of all dinosaurs that are more closely related to birds than to oviraptorosaurs

Paraves are a widespread group of theropod dinosaurs that originated in the Middle Jurassic period. In addition to the extinct dromaeosaurids, troodontids, anchiornithids, and possibly the scansoriopterygids, the group also contains the avialans, which include diverse extinct taxa as well as the over 10,000 species of living birds.

Zhongornis is a genus of primitive maniraptoran dinosaurs that lived during the Early Cretaceous. It was found in rocks of the Yixian Formation in Lingyuan City (China), and described by Gao et al. in 2008.

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

Epidexipteryx is a genus of small maniraptoran dinosaurs, known from one fossil specimen in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. Epidexipteryx represents the earliest known example of ornamental feathers in the fossil record.

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

Xiaotingia is a genus of anchiornithid theropod dinosaur from Middle Jurassic or early Late Jurassic deposits of western Liaoning, China, containing a single species, Xiaotingia zhengi.

<span class="mw-page-title-main">Jinfengopteryginae</span> Extinct subfamily of dinosaurs

Jinfengopteryginae is a subfamily of bird-like theropod dinosaurs known from the Cretaceous of Eurasia. This group includes relatively few genera, with members discovered in 2005 but the name erected in 2012. Like other troodontids, this group of dinosaurs resided in the Paraves potentially close to the Avialae.

<span class="mw-page-title-main">Timeline of troodontid research</span> Events in the history of paleontology

This timeline of troodontid research is a chronological listing of events in the history of paleontology focused on the troodontids, a group of bird-like theropod dinosaurs including animals like Troodon. Troodontid remains were among the first dinosaur fossils to be reported from North America after paleontologists began performing research on the continent, specifically the genus Troodon itself. Since the type specimen of this genus was only a tooth and Troodon teeth are unusually similar to those of the unrelated thick-headed pachycephalosaurs, Troodon and its relatives would be embroiled in taxonomic confusion for over a century. Troodon was finally recognized as distinct from the pachycephalosaurs by Phil Currie in 1987. By that time many other species now recognized as troodontid had been discovered but had been classified in the family Saurornithoididae. Since these families were the same but the Troodontidae named first, it carries scientific legitimacy.

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

Anchiornithidae is a family of small paravian dinosaurs. Anchiornithids have been classified at varying positions in the paravian tree, with some scientists classifying them as a distinct family, a basal subfamily of Troodontidae, members of Archaeopterygidae, or an assemblage of dinosaurs that are an evolutionary grade within Avialae or Paraves.

References

  1. ↑ Zhang, H.; Wang, M.; Liu, X. (2008). "Constraints on the upper boundary age of the Tiaojishan Formation volcanic rocks in West Liaoning-North Hebei by LA-ICP-MS dating". Chinese Science Bulletin. 53 (22): 3574–3584. Bibcode:2008SciBu..53.3574Z. doi:10.1007/s11434-008-0287-4.
  2. ↑ Barrett, P. M. (2009). "The affinities of the enigmatic dinosaur Eshanosaurus deguchiianus from the Early Jurassic of Yunnan Province, People's Republic of China". Palaeontology. 52 (4): 681−688. Bibcode:2009Palgy..52..681B. doi:10.1111/j.1475-4983.2009.00887.x.
  3. 1 2 Holtz, T.R. and Osmólska, H. (2004). "Saurischia." In Weishampel, Dodson and Osmólska (eds.), The Dinosauria, second edition. Berkeley: University of California Press.
  4. 1 2 3 Turner, A.H.; Pol, D.; Clarke, J.A.; Erickson, G.M.; Norell, M. (2007). "A basal dromaeosaurid and size evolution preceding avian flight" (PDF). Science. 317 (5843): 1378–1381. Bibcode:2007Sci...317.1378T. doi: 10.1126/science.1144066 . PMID   17823350. S2CID   2519726.
  5. ↑ Xu, X.; Tang, Z-L.; Wang, X-L. (1999). "A therizinosauroid dinosaur with integumentary structures from China". Nature. 399 (6734): 350–354. Bibcode:1999Natur.399..350X. doi:10.1038/20670. S2CID   204993327.
  6. ↑ Xu X., Zheng X.-t. and You, H.-l. (2009). "A new feather type in a nonavian theropod and the early evolution of feathers." Proceedings of the National Academy of Sciences (Philadelphia), doi : 10.1073/pnas.0810055106
  7. ↑ Chiappe, L.M. (2007). Glorified Dinosaurs: The Origin and Early Evolution of Birds. Sydney: UNSW Press.
  8. ↑ Scientists find a new dinosaur with well preserved, bird-like wings — but not for flight
  9. ↑ Paul, G.S. (2002). Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Baltimore: Johns Hopkins University Press.
  10. 1 2 Zanno, L.E., Gillette, D.D., Albright, L.B., and Titus, A.L. (2009). "A new North American therizinosaurid and the role of herbivory in 'predatory' dinosaur evolution." Proceedings of the Royal Society B, Published online before print July 15, 2009, doi : 10.1098/rspb.2009.1029.
  11. ↑ Meso, Jorge Gustavo; Pol, Diego; Chiappe, Luis; Qin, Zichuan; Díaz-Martínez, Ignacio; Gianechini, Federico; Apesteguía, Sebastián; Makovicky, Peter J.; Pittman, Michael (2024). "Body size and evolutionary rate analyses reveal complex evolutionary history of Alvarezsauria". Cladistics. n/a (n/a). doi:10.1111/cla.12600. ISSN   1096-0031.
  12. ↑ Chiappe, L.M. (1995). "The first 85 million years of avian evolution". Nature. 378 (6555): 349–355. Bibcode:1995Natur.378..349C. doi:10.1038/378349a0. S2CID   4245171.
  13. ↑ Foth, Christian; Tischlinger, Helmut; Rauhut, Oliver (2014). "New specimen of Archaeopteryx provides insights into the evolution of pennaceous feathers". Nature. 511 (7507): 79–82. Bibcode:2014Natur.511...79F. doi:10.1038/nature13467. PMID   24990749.
  14. ↑ Gauthier, J. and de Queiroz, K. (2001). "Feathered dinosaurs, flying dinosaurs, crown dinosaurs, and the name 'Aves'". Pp. 7-41 in Gauthier, J. and L.F. Gall (eds.), New Perspectives on the Origin and Early Evolution of Birds: Proceedings of the International Symposium in Honor of John H. Ostrom. New Haven: Peabody Museum of Natural History, Yale University. ISBN   0-912532-57-2.
  15. ↑ Sorkin, Boris (2021-12-02). "Scansorial and aerial ability in Scansoriopterygidae and basal Oviraptorosauria". Historical Biology. 33 (12): 3202–3214. Bibcode:2021HBio...33.3202S. doi:10.1080/08912963.2020.1855158. ISSN   0891-2963.
  16. ↑ Cau, Andrea. “The body plan of Halszkaraptor escuilliei (Dinosauria, Theropoda) is not a transitional form along the evolution of dromaeosaurid hypercarnivory.” PeerJ vol. 8 e8672. 25 Feb. 2020, doi:10.7717/peerj.8672
  17. ↑ Czerkas, S.A., and Yuan, C. (2002). "An arboreal maniraptoran from northeast China." Pp. 63-95 in Czerkas, S.J. (Ed.), Feathered Dinosaurs and the Origin of Flight. The Dinosaur Museum Journal 1. The Dinosaur Museum, Blanding, U.S.A. PDF abridged version
  18. ↑ Zhang, F., Zhou, Z., Xu, X. & Wang, X. (2002). "A juvenile coelurosaurian theropod from China indicates arboreal habits." Naturwissenschaften, 89(9): 394-398. doi:10.1007 /s00114-002-0353-8.
  19. ↑ Longrich, Nicholas R.; Currie, Philip J. (2009). "Albertonykus borealis, a new alvarezsaur (Dinosauria: Theropoda) from the Early Maastrichtian of Alberta, Canada: Implications for the systematics and ecology of the Alvarezsauridae". Cretaceous Research. 30 (1): 239–252. Bibcode:2009CrRes..30..239L. doi:10.1016/j.cretres.2008.07.005.
  20. ↑ Holtz, T.R. Jr.; Brinkman, D.L.; Chandler, C.L. (1998). "Dental morphometrics and a possibly omnivorous feeding habit for the theropod dinosaur Troodon". GAIA. 15: 159–166.
  21. ↑ Tagliavento, Mattia; Davies, Amelia J.; Bernecker, Miguel; Fiebig, Jens (April 3, 2023). "Evidence for heterothermic endothermy and reptile-like eggshell mineralization in Troodon, a non-avian maniraptoran theropod". PNAS . 120 (15): e2213987120. Bibcode:2023PNAS..12013987T. doi:10.1073/pnas.2213987120. PMC   10104568 . PMID   37011196.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.