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Information about Achillobator

Achillobator
Fossil range: Late Cretaceous
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Achillobator giganticus

Achillobator giganticus
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Sauropsida
Superorder:Dinosauria
Order:Saurischia
Suborder:Theropoda
Infraorder:Coelurosauria
Family:Dromaeosauridae
Subfamily:Dromaeosaurinae
Genus:Achillobator
Species:A. giganticus
Binomial name
Achillobator giganticus
Perle, Norell, & Clark, 1999
Achillobator (IPA: /æˌkɪloʊˡbɑtɔɹ/; "Achilles' warrior/hero") is a genus of dromaeosaurid theropod dinosaur from the Late Cretaceous Period of what is now Central Asia. It was probably an active bipedal predator, hunting with the large sickle-shaped claw on the second toe of each hind foot. It was a large dromaeosaurid, between 15 and 20 feet (4.6 to 6 meters) from snout to tail.

Discovery and species

The generic name comes from Achilles, a famous ancient Greek warrior of the Trojan War, and the Mongolian word bator ("warrior" or "hero"). It refers to the large Achilles tendon needed to use the sickle claw on the foot, which was the major combat organ of dromaeosaurids. The one species is named A. giganticus because it is much larger than most other dromaeosaurids. This dinosaur was first described in 1999[1] by Mongolian paleontologist Altangerel Perle, and Americans Mark Norell and Jim Clark, although the description is not complete and was actually published without the knowledge of the latter two authors. A more complete description may be forthcoming.

Fossil bones of Achillobator were found mostly disarticulated, but associated, including a fragment of the upper jaw with teeth, as well as vertebrae from all sections of the spinal column, ribs, and bones from the shoulder, pelvis, forelimbs, and hindlimbs.

These remains were found in the Bayan Shireh Formation of Dornogovi Province, Mongolia, which dates back to the Late Cretaceous Period. The exact age is unknown, with two main competing hypotheses. Based on comparisons with other formations, the Bayan Shireh fauna seems to correspond best with the Turonian through early Campanian stages of the Late Cretaceous, about 93 to 80 million years ago.[2] However, examination of the magnetostratigraphy of the formation seems to confirm that the entire Bayan Shireh lies within the Cretaceous Long Normal, which lasted only until the end of the Santonian, giving a possible Cenomanian through Santonian age, or between 98 and 83 million years ago.[3] Some other dinosaurs found in the Bayan Shireh are Alectrosaurus, Segnosaurus, Talarurus, and Bactrosaurus.

Classification

Achillobator is probably a dromaeosaurid, a family of dinosaurs currently thought to be very closely related to birds. While the relationships of dromaeosaurids to other theropods (including birds) is relatively well-understood, the phylogeny within the family itself is not. The most recent analysis shows Achillobator as a member of the subfamily Dromaeosaurinae, most closely related to animals like Adasaurus, also from Mongolia, as well as North American forms like Utahraptor and Dromaeosaurus. Deinonychus and Velociraptor are also dromaeosaurines, but appear to represent a different branch of the subfamily.[4]

Chimera theory

The pelvis of Achillobator seems to show plesiomorphic ("primitive") saurischian characteristics compared to other dromaeosaurids. For instance, the pubis is aligned vertically and has a large pubic boot (a wide expansion at the end), unlike most other dromaeosaurids, where there is a much smaller boot, if any, and the pubis points backwards in the same direction as the ischium (a condition called opisthopuby, which is also seen in the unrelated therizinosaurs and ornithischians, as well as in birds).

The above differences and others have led to suggestions that Achillobator represents a paleontological chimera.[5] However, other studies refute this, noting that many pieces were found semi-articulated, and that Achillobator routinely comes out as a dromaeosaurid in cladistic analyses, even taking into account the differences.[6]

References

1. ^ Perle A, Norell MA & Clark J. 1999. A new maniraptoran theropod - Achillobator giganticus (Dromaeosauridae) - from the Upper Cretaceous of Burkhant, Mongolia. Contributions of the Mongolian-American Paleontological Project 101: 1–105.
2. ^ Jerzykiewicz T & Russell DA. 1991. Late Mesozoic stratigraphy and vertebrates of the Gobi Basin. Cretaceous Research 12(4): 345-377.
3. ^ Hicks JF, Brinkman DL, Nichols DJ & Watabe M. 1999. Paleomagnetic and palynological analyses of Albian to Santonian strata at Bayn Shireh, Burkhant, and Khuren Dukh, eastern Gobi Desert, Mongolia. Cretaceous Research 20(6): 829-850.
4. ^ Makovicky JA, Apesteguía S & Agnolín FL. 2005. The earliest dromaeosaurid theropod from South America. Nature 437: 1007-1011.
5. ^ Burnham DA, Derstler KL, Currie PJ, Bakker RT, Zhou Z, & Ostrom JH. 2000. Remarkable new birdlike dinosaur (Theropoda: Maniraptora) from the Upper Cretaceous of Montana. University of Kansas Paleontological Contributions 13: 1-14.
6. ^ Norell MA & Makovicky JA. 2004. Dromaeosauridae. In Weishampel, D.B., P. Dodson, & H. Osmolska (eds.). The Dinosauria (2nd Edition). Berkeley: University of California Press. Pp. 196-209.


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Late Cretaceous (100mya - 65mya) refers to the second half of the Cretaceous Period, named after the famous white chalk cliffs of southern England, which date from this time. Rocks deposited during the Late Cretaceous Period are referred to as the Upper Cretaceous Series.
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Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. Scientific classification also can be called scientific taxonomy, but should be distinguished from folk taxonomy, which lacks scientific basis.
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Chordata
Bateson, 1885

Typical Classes

See below

Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates.
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Sauropsida*
Goodrich, 1916

Subclasses
  • Anapsida
  • Diapsida
Synonyms
  • Reptilia Laurenti, 1768
Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class
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Dinosauria *
Owen, 1842

Orders & Suborders
  • Ornithischia
  • Cerapoda
  • Thyreophora
  • Saurischia

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Saurischia
Seeley, 1887

Suborders
  • Theropoda
  • Sauropodomorpha


Saurischia (from the Greek sauros (σαυρος) meaning 'lizard' and ischion (
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Theropoda
Marsh, 1881

Infraorders
  • Carnosauria
  • Ceratosauria
  • Deinonychosauria
  • Ornithomimosauria
  • Oviraptorosauria


Theropods ('beast feet') are a group of bipedal saurischian dinosaurs.
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Coelurosauria
von Huene, 1914

Sub-groups
  • Compsognathidae
  • Maniraptora
  • Ornithomimosauria
  • Tyrannosauroidea
Coelurosauria is a diverse group of theropod dinosaurs that includes a number of subgroups, such as Tyrannosauroidea,
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Dromaeosauridae
Matthew & Brown, 1922

Genera

See text.

Dromaeosauridae is a family of bird-like theropod dinosaurs. They were mainly small, gracile carnivores that flourished in the Cretaceous Period.
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Dromaeosauridae
Matthew & Brown, 1922

Genera

See text.

Dromaeosauridae is a family of bird-like theropod dinosaurs. They were mainly small, gracile carnivores that flourished in the Cretaceous Period.
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binomial nomenclature is the formal system of naming species. The system is also called binominal nomenclature (particularly in zoological circles), binary nomenclature (particularly in botanical circles), or the binomial classification system.
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20th century - 21st century
1960s  1970s  1980s  - 1990s -  2000s  2010s  2020s
1996 1997 1998 - 1999 - 2000 2001 2002

Year 1999 (MCMXCIX
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This chart shows concisely the most common way in which the International Phonetic Alphabet (IPA) is applied to represent the English language.

See International Phonetic Alphabet for English for a more complete version and Pronunciation respelling for English for phonetic
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genus (plural: genera) is part of the Latinized name for an organism. It is a name which reflects the classification of the organism by grouping it with other closely similar organisms.
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Dromaeosauridae
Matthew & Brown, 1922

Genera

See text.

Dromaeosauridae is a family of bird-like theropod dinosaurs. They were mainly small, gracile carnivores that flourished in the Cretaceous Period.
..... Click the link for more information.
Theropoda
Marsh, 1881

Infraorders
  • Carnosauria
  • Ceratosauria
  • Deinonychosauria
  • Ornithomimosauria
  • Oviraptorosauria


Theropods ('beast feet') are a group of bipedal saurischian dinosaurs.
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Dinosauria *
Owen, 1842

Orders & Suborders
  • Ornithischia
  • Cerapoda
  • Thyreophora
  • Saurischia

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The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i.e. from 145.5 ± 4.0 million years ago (Ma)) to the beginning of the Paleocene epoch of the Tertiary Period (about 65.5 ± 0.3 Ma).
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A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. The equivalent term used to demarcate rock layers and the fossil record is the system; thus the rocks of the Devonian System were laid down during the Devonian Period.
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Central Asia is a vast landlocked region of Asia. Though various definitions of its exact composition exist, no one definition is universally accepted. Despite this uncertainty in defining borders, it does have some important overall characteristics.
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Bipedalism is standing, or moving for example by walking, running, or hopping, on two appendages (typically legs). An animal or machine that usually moves in a bipedal manner is known as a biped (/'baɪ.
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predation describes a biological interaction where a predator organism feeds on another living organism or organisms known as prey.[1] Predators may or may not kill their prey prior to feeding on them.
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A claw is a curved pointed appendage, found at the end of a toe or finger or, in arthropods, of the tarsus.

Arthropods

The correct term for an arthropod's 'claw' is a chela (plural chelae). Legs bearing a chela are called chelipeds.
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Achilles (also Akhilleus or Achilleus; Ancient Greek: Άχιλλεύς) was a hero of the Trojan War, the central character and greatest warrior of Homer's Iliad
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Greek mythology is the body of stories belonging to the Ancient Greeks concerning their gods and heroes, the nature of the world and the origins and significance of their own cult and ritual practices.
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Trojan War was waged, according to Greek mythology, against the city of Troy by the armies of the Achaeans (Mycenaean Greeks), after Paris of Troy stole Helen from her husband Menelaus, king of Sparta.
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The Mongolian language (монгол хэл, mongol khel) is the best-known member of the Mongolic language family and the primary language of most of the residents of Mongolia, where
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Achilles tendon (or occasionally Achilles’ tendon) also known as the calcaneal tendon or the tendocalcaneous is a tendon of the posterior leg. It serves to attach the gastrocnemius (calf) and soleus muscles to the calcaneus (heel) bone.
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species is one of the basic units of biological classification. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
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