NEWS :
13. 10. 2005 - Sebastián Apesteguía, Federico Agnolín Novas and Peter Makovicky discover the remains of Buitreraptor gonzalezorum in the sandstones of La Buitrera, Rio Negro, in the north-west of Patagonia, Argentina. The new species displays characters also known from Troodontidae and Aves. It also is remarkable for it's completely unserrated teeth!2. 12. 2005 - A new specimen of Archaeopteryx has surfaced from a private collection and become available for research. Several characters, which were not well visible in previous known Archaeopteryx-Fossils or not well preserved, are clearly visible in the "new" excellently preserved specimen . As did the Deinonychosauria, Archaeopteryx possessed an enlarged hyperextendable second pedal ungual (claw on the 2nd toe) and the hallux (1st toe) was not opposable to the other toes. While the former is yet further proove that our modern birds are truly theropods, the latter points strongly towards Archaeopteryx never spent as much time in trees as many thought it would have (thus strengthening the "grounds up" - hypothesis concerning the evolution of powered flight)!
Format:
Alpha
|--Beta
`--Gamma
|--Delta
|*-Epsilon
`--Zeta
|?-Eta
`--Theta
Beta and Gamma are sister taxa (Species) within the clade (group) Alpha. Delta is within Gamma, but not a member of Zeta. Epsilon, however, is Gamma incertae sedis (uncertain position). Eta is only
tentatively placed within Zeta. Nomina nuda ("Naked name" species description considered invalid because either the specimen/s it was based on was/were lost or the material was considered inadequate) are non-italicized and placed in quotation marks, while unpublished taxa [as recognized by the ICZN] are designated
the same way, but followed by an asterisk. Nomina dubia (Species "in doubt" meaning it's not for certain, wether this actually is a valid species) are not distinguished from valid taxa, as which taxa are indeterminate is a subjective question.
Theropoda | Avepoda Averostra Neotheropoda | Ceratosauroidea | Tetanurae | Avetheropoda | Coelurosauria | Avipluma Tyrannoraptora | Metatheropoda | Maniraptoriformes | Maniraptora | Paraves Eumaniraptora | |--Deinonychosauria | Dromaeosauridae | |--Microraptoria | | |--Graciliraptor lujiatunensis | | |--Sinornithosaurus millenii | | `--+--Cryptovolans pauli | | |--Microraptor gui | | `--Microraptor zhaoianus | |--Bambiraptor feinbergi | |*?"Airakoraptor" | |*-"Dromaeosaurus" gracilis | |*?"Ichabodcraniosaurus" | |*-Itemirus medullaris | |*-"Laelaps" explanatus | `--+--Velociraptorinae | | `--Velociraptor mongoliensis | |?-Saurornitholestes langstoni | |*-"Koreanosaurus koreanensis" | |*-Ornithodesmus cluniculus | |*-Pyroraptor olympius | |*-Variraptor mechinorum | `--Dromaeosaurinae | |--Deinonychus antirrhopus | `--+--Atrociraptor marshalli | |?-Dromaeosauroides bornholmensis | `--+--Dromaeosaurus albertensis | |?-Adasaurus mongoliensis | |--Achillobator giganticus | `--Utahraptor ostrommaysorum |--Troodontidae | |*-Yaverlandia bitholus | |--Mei long | `--+--Sinovenator changiae | |--Jinfengopteryx elegans | `--+--Sinusonasus magnodens | |--Koparion douglassi | |*?"Ornithomimus" tenuis | `--+--Byronosaurus jaffei | `--+--Sinornithoides youngi | `--+*-Borogovia gracilicrus | |*-Saurornithoides? asiamericanus | |*-Saurornithoides? isfarensis | |*-Tochisaurus nemegtensis | |--Troodon formosus | `--+--Saurornithoides mongoliensis | `--Saurornithoides junior `--Avialae
The main informations we can get out of this cladogramm are the following:
Distribution: Fossil remains of Deinonychosauria (including Troodontidae) have been described from all over the world.
Timeline: The following table shows when the different species lived and who described them ("correctly" - according to present knowledge) for the first time.
1. Deinonychosauria were a sister group to birds. More so were the Troodontidae.
2. Deinonychosauria (and Troodontidae) represent a group of highly specialized, "advanced" animals.
3. Deinonychosauria shared a common ancestor with the Avialae (birds) and the Troodontidae which explains why they were so bird-like.