Dromaeosauridae

   Dromaeosauridae includes the famous "raptors" of Jurassic Park, which apparently have gone bald through the insertion of frog DNA.  It is likely that all dromaeosaurids had a protofeather coating and probably display feathers as well.  Dromaeosaurids are most often recognized for their feet; the second toe is hyperextendable and bears a large claw which could be slashed down in a narrow plane of vertical movement.  Dromaeosaurids also have tails stiffened by the chevrons and vertebral processes.  The tail can only move up and down close to the body, where it can bend nearly 90 degrees straight up, as illustrated by the famous "fighting" Velociraptor specimen.  The tail thus behaves like a single straight unit, useful for balance.
    It has long been thought that the sickle claw was a slicing weapon, used in a nasty way to cut things open. Unsurprisingly, this model caught the public imagination; a big slicing implement is always impressive, even when it could be positioned more conveniently, feet being what (and where) they are.  However, the cross-section of the claw shows a rather broad leading edge for a knife, and two independent studies have suggest a piercing use.  In 2009, a study came out proposing a climbing crampon function: instead of slicing up prey, dromaeosaurids would have hooked onto prey animals and then bit the heck out of them.  Yet another alternate function was proposed in 2011: that the feet were used to grip and hold down prey of similar or smaller size. It would be interesting if more than one of these functions were possible, or if different dromies were more capable of one function than another. I suppose that, if you should be taking a time-travel safari, you should probably leave the dromies alone.
    As with several other maniraptoran clades, the arrangement of taxa here is particularly volatile and subject to change.  Recent work has found dromie-things in abundance in China and the Gondwanan continents (South America and Madagascar, particularly), with uncertain relationships to dromaeosaurids proper and uncertain claims on flight.  I'm not sure how the terminology will sort out when the dust clears; perhaps a Dromaeosauroidea is in order, to host Dromaeosauridae, Unenlagiidae, and Microraptoria, or something like that.  Semantics and taxonomy are pretty academic, anyway.  Unenlagia and its allies may form a Gondwanan radiation of small flying or flying-like long-snouted basal dromies, while Microraptor and its allies are mostly tiny basal dromies from Asia, also with aerial pretensions.  Both of these groups get into the netherworld where basal troodontids, basal dromaeosaurids, basal avialans, and other maniraptorans cavort.

<--Dromaeosauridae
     |--Mahakala
     `--+--Unenlagiinae
          |    |--Rahonavis
          |    `--+--Austroraptor
          |         |--Buitreraptor
          |         |--Neuquenraptor
          |         `--Unenlagia
          `--+--Microraptoria
               |    |--Graciliraptor
               |    |--Hesperonychus
               |    |--Microraptor  
               |    |--Shanag
               |    |--Sinornithosaurus
               |    `--?Tianyuraptor
               `--Eudromaeosauria
                    |--Saurornitholestinae
                    |    |--Atrociraptor
                    |    |--Bambiraptor
                    |    `--Saurornitholestes
                    `--+--Deinonychus
                         |--Dromaeosaurinae
                         |    |--Achillobator
                         |    |--Dromaeosaurus
                         |    `--Utahraptor
                         `--Velociraptorinae
                              |--+--Adasaurus
                              |    `--Itemirus
                              `--+--Tsaagan
                                   `--Velociraptor

Dromaeosauridae: Numerous unnamed and indeterminate dromaeosaurids are known, including a large dromaeosaurid from the Cenomanian (LK) of Sudan, dromaeosaurids from the LK of Romania, several forms from Mongolia, possible Jurassic examples from Asia (Callovian [MJ] of Kyrgyzstan?), Europe, and North America, and additional American forms in the Cloverly and Judithian-Edmontonian-Lancian succession.
   The "raptors" of Jurassic Park, while ostensibly Velociraptor individuals, were actually oversized Deinonychus individuals, a calculated mix-up which stems from a period of time in the late 1980s when some workers considered the two to be in the same genus.  For the purposes of the book, Deinonychus is quite a bit larger than Velociraptor (around knee-high at the hips), making it more threatening.  For the purposes of the movies, Deinonychus wasn't large enough (think of waist-height at the hips at best), so the size was bumped up while retaining the evocative name.  This was speculative at the time, but even larger dromaeosaurids have since been found (Utahraptor, Achillobator), showing the JP 'raptors to be well within the realm of possible dromie dimensions.

Taxon or Taxa: Time/Place: Comments:
Mahakala omnogovae Turner, Pol, Clarke, Erickson, and Norell, 2007 late Campanian (LK) of Mongolia Mahakala is a little dromie (~70 cm long) and very basal as well; it shows characteristics found in basal members of other related groups (troodontids and birds) and features lost in more derived dromaeosaurids.  It's know from a decent chunk of a skeleton and skull from a nearly grown individual.  The tiny size suggests that this feature preceded flight in bird evolution.

Dromaeosauridae i.s.:

Taxon or Taxa: Time/Place: Comments:
Balaur bondoc Csiki, Brusatte, and Norell, 2010 early-mid Maastrichtian (LK) of Romania Balaur is a robust Velociraptor-like dromaeosaurid based on a partial skeleton that includes most of the limbs and trunk region (parts of both the shoulder and pelvic girdles, and some dorsal, sacral, and caudal verts).  Its hands had a high degree of fusion, with the third fingers more or less splints, while the feet had paired enlarged "killer claws": both the first and the typical second claws.
Dromaeosauroides bornholmensis Christiansen and Bonde, 2003 late Berriasian-Valanginian (EK) of Denmark Denmark's first named classic dinosaur is a dromaeosaurid based on a tooth, thought to be close to Dromaeosaurus itself (hence the name).
"Kitadanisaurus" (N.N.) Lambert, 1990 Barremian (EK) of Japan "Kitadanisaurus" is kind of a placeholder for Japanese dromaeosaurid pieces-parts.
Linheraptor exquisitus Xu X., Choiniere, Pittman, Tan Q., Xiao D., Li Z. Q., Tan L., Clark, Norell, Hone, and Sullivan, C., 2010  late Campanian (LK) of China Linheraptor is a Tsaagan-like dromaeosaurid known from a nearly complete and articulated skeleton (hence the "exquisitus"), so think classic Late Cretaceous Asian dromaeosaurid, with the elongate depressed snout and body length just shy of 2 m.
Luanchuanraptor henanensis Lü J., Xu L., Zhang X., Ji Q., Jia S., Hu W., Zhang J., and Wu Y., 2007 LK of China Luanchuanraptor, a medium-sized dromaeosaurid, is the first Asian dromaeosaurid described from outside the Gobi Desert or northeastern China.  It is known from a partial skeleton including a frontal, around 20 verts, a humerus, partial girdles, and miscellaneous fragmentary bones.
?Nuthetes destructor (N.D.) Owen, 1854 early Berriasian (EK) of England This taxon from the early days of dinosaur paleo is still very much a mystery.  It has been at times considered a lizard or a juvenile "megalosaur".  Originally referred to it were ?armor scutes which had been reassigned to the somewhat better known ornithischian Echinodon, but are more likely from a turtle's limbs.  The remains left behind, particularly the type, a dentary fragment with teeth, appear to pertain to a dromaeosaurid.
?Pamparaptor micros Porfiri, Calvo, and Santos, 2011 Coniacian (LK) of Argentina Known from a partial left foot once thought to belong to an immature Neuquenraptor, Pamparaptor may be a basal dromaeosaurid with similarities to troodontids. It was a small animal, with the holotype individual estimated at 0.5 to 0.7 m long.
Pyroraptor olympius Allain and Taquet, 2000 late Campanian-early Maastrichtian (LK) of France Possibly the same as Variraptor, Pyroraptor earned its name because the type material was discovered after a forest fire.  It is based on a "killer claw," with additional remains referred to it.
?Unquillosaurus ceibalii Powell, 1979 ?Campanian (LK) of Argentina It is not certain where this theropod belongs, but recent restudy indicates that it is a derived coelurosaur, possibly related to the dromaeosaurids.  It is based on a pubis that appears to show opisthopuby.  It may be the same as another already named theropod for which the pubis is unknown.  Originally described as over 11 meters in length, this animal would have been much closer to 2 or 3 meters long.  It could be related to the unenlagiines.

Unenlagiinae: Standard issue long-snouted Gondwanan basal dromies.  Except, of course, that they were taking on roles that Laurasian dromies seem not to have been doing in the LK, including small winged forms and medium-sized short-armed predators.

Taxon or Taxa: Time/Place: Comments:
Rahonavis ostromi Forster, Sampson, Chiappe, and Krause, 1998 (originally Rahona ostromi Forster et al., 1998) mid Maastrichtian (LK) of Madagascar Very much like a small, almost-flying dromaeosaurid, Rahonavis had to be renamed because its original name was preoccupied (Griveaud, 1975).
Austroraptor cabazai Novas, Pol, Canale, Porfiri, and Calvo, 2008 Campanian-Maastrichtian (LK) of Argentina Austroraptor, unlike others of its unenlagiine compatriots (and dromaeosaurids in general), had short arms.  It also happened to be about 5 m long, and it had an elongate skull with an Irritator-like profile.  Short-armed oversized spinosaur-skulled dromaeosaurids are something of a novelty, and Austroraptor provides more evidence that Gondwanan dromaeosaurids were taking the dromaeosaurid concept to unexpected places.
Note that "Austroraptor" is also a pre-publication name mooted for the theropod Ozraptor, which oddly enough was at one time thought to be a dromaeosaurid.
Buitreraptor gonzalezorum Makovicky, Apesteguía, and Agnolín, 2005 Cenomanian (LK) of Argentina Buitreraptor is known from two individuals, including a nearly-complete scavenged skeleton that serves as its type, the best skeleton of a small nonavian theropod from South America (I've heard best nonavian theropod period, but it's got some stiff competition from abelisaurids Carnotaurus and Aucasaurus).  It had a very long skull (>25% larger than femur) mostly made up of snout, with small unserrated teeth.  The foot has the noncommittal basal dromie-thing arctomet.  The long arm and other characters suggest a genuine flyer.  Me, I'm hoping for a nice skeletal restoration soon.
Neuquenraptor argentinus Novas and Pol, 2005 (?Unenlagia) Coniacian (LK) of Argentina Perhaps you knew this as "Araucanoraptor argentinus", possible troodontid.  Put all of the material together, and you get a good chunk of hindlimb (including the all-important foot), part of a cervical, ribs, and a partial radius.  It adds up to a basal dromaeosaurid that teams up with Unenlagia (or is the same thing) to hint at a hitherto-unappreciated deinonychosaurian radiation in Gondwana, and also illustrates that arctomets were useful to a variety of coelurosaurians, but quite a bit more complicated for people trying to understand their evolution (it has the famous arctomet, which is why it was first identified as a troodontid).
Unenlagia: Novas and Puerta, 1997 U. comahuensis (type) Novas and Puerta, 1997 Coniacian (LK) of Argentina One of several bizarre birdlike (although new restorations indicate its shoulder wasn't as birdlike as once thought) theropods named from Argentina in recent years, current thought puts Unenlagia with the dromaeosaurids.  It was briefly put forward as a juvenile of Megaraptor.
U. paynemili Calvo, Porfiri, and Kellner, 2004 This species just came out of nowhere for a lot of us North American dinosaur enthusiasts, mentioned briefly in the description of Buitreraptor.

Microraptoria: This is a possible, newly-assembled grouping of the Yixian "microraptors," the little dromie-ish beasties with feathers and, in some cases, wings. 

Taxon or Taxa: Time/Place: Comments:
Graciliraptor lujiatunensis Xu and Wang, 2004 Barremian-early Aptian (EK) of China From the lower part of the Yixian, this dromaeosaurid is based on a partial maxilla, caudals (elongated), and partial fore and hindlimbs.  It may form a clade with other Yixian dromaeosaurids\deinonychosaurians.  Like other basal dromie\deinonychosaur-type theropods, it has a "subarctomet" metatarsus (partial compression and overlap of the two flanking metatarsals on MT III).
Hesperonychus elizabethae Longrich and Currie, 2009 late middle or early late Campanian (LK) of Alberta Hesperonychus is the smallest known carnivorous dinosaur from North America, at around 2 kilograms (4 and a half pounds) in weight.  It's based on a partial pelvis that was discovered back in 1982 but for whatever reason did not attract attention at the time.  Various bits and pieces of tiny dromies probably belong to it, making it relatively common.  It's also the first known North American microraptorian.
Shanag ashile Turner, Hwang, and Norell, 2007 EK of Mongolia Shanag is based on a maxilla, dentary, and splenial (one of those lower jaw bones you don't think about much).  It had an extra hole in the maxilla and some extra pneumatic cavities, and was similar to Yixian dromaeosaurids.
Sinornithosaurus: Xu, Wang, and Wu, 1999 S. millenii (type) Xu, Wang, and Wu, 1999 early Aptian (EK) of China Another Yixian theropod, this one also possesses protofeathers.  It seems to be close to the base of Dromaeosauridae.  It is slightly arctomet, with a foot vaguely troodontid in other ways as well.  The skull is reminiscent of Archaeopteryx.
S. haoianus Liu J., Ji S., Tang F., and Gao C., 2004 The second species is based on an incomplete skeleton, with long arms and big thumb claws.
There've been some feathers flying about the species name, which I've amended from haoiana because I usually go along with these emendations.
?Tianyuraptor ostromi Zheng X., Xu X., You H., Zhao Q., and Dong Z., 2009  Barremian-early Aptian (EK) of China For variety's sake, this Yixian dromie was fairly large (on the order of a couple meters long), with short arms and long legs. 
Microraptor zhaoianus Xu, Zhou, and Wang, 2000 (?including M. gui [Xu, Zhou, Wang, Kuang, Zhang, and Du, 2003], Cryptovolans pauli [Czerkas, Zhang, Li J., and Li Y., 2002]) early Aptian (EK) of China Another in the cavalcade of feathered theropods, this animal was smaller than Archaeopteryx as an adult.  It may have been arboreal.  Interestingly, the dromaeosaurid-type tail grafted on the remains of the infamous "Archaeoraptor" belongs to this taxon (the rest of which has been named Archeovolans repatriatus Czerkas and Xu, 2002, a bird genus that depending on how derived it is may or may not eventually warrant an entry here).  It may be close to the common ancestor of the troodontids, dromaeosaurids, and "Aves", or a true dromaeosaurid, or it might just be happy hanging around with the other Yixian mini-deinonychosaurs as a microraptorian.
M. zhaoianus is probably the same as M. gui and Cryptovolans pauli.  M. gui, known from possibly several individuals, is notable for showing what is very similar to flight feathers not only on the arms, but also on the legs (inspiring the "four-winged dinosaur").  If capable of flight, it represents a method unlike modern analogues, and could represent a failed experiment in the early radiation of flight.

Eudromaeosauria:

Taxon or Taxa: Time/Place: Comments:
Deinonychus antirrhopus Ostrom, 1969 Aptian-Albian (EK) of Montana, Wyoming, Utah, Oklahoma, and Maryland Possibly the most important classic dinosaur to be described in the latter half of the twentieth century, Deinonychus is widely credited with spurring on the "Dinosaur Revolution" that overturned much of the thinking that had dominated dinosaur paleontology since the Twenties, especially the idea that all dinosaurs were slow, cold-blooded, stupid dead-ends.  Deinonychus was shown to be fast, relatively smart, and closely related to birds, reviving the idea that birds are descendants of dinosaurs.  It is also a close relative of Velociraptor.  Associations of teeth with bones of Tenontosaurus suggests that this large ornithopod was a fairly common food item.  Some researchers have suggested that it hunted in packs, but evidence to support this claim is ambiguous.

Saurornitholestinae:

Taxon or Taxa: Time/Place: Comments:
Atrociraptor marshalli Currie and Varricchio, 2004 late Campanian-middle Maastrichtian (LK) of Alberta From the Horseshoe Canyon Formation, Atrociraptor is based on a partial snout and lower jaws.  The muzzle is shorter and taller than those of other roughly contemporaneous dromaeosaur-type things, and the animal itself is one of the smaller dromaeosaurids.  It is described as the sister taxon to Deinonychus.
Bambiraptor feinbergorum Burnham, Derstler, Currie, Bakker, Zhou, and Ostrom, 2000 middle-late Campanian (LK) of Montana Based on a partial subadult (approximately three-quarters adult size) skeleton originally referred to Velociraptor, the unfortunately-named Bambiraptor is another derived theropod, possibly close to the base of Dromaeosauridae, or maybe the same thing as Saurornitholestes.  So far, it is the only dinosaur known to have had opposable fingers (I and III).
Saurornitholestes: Sues, 1978 S. langstoni (type) Sues, 1978 late middle-early late Campanian (LK) of Alberta Saurornitholestes appears in some ways to be between Velociraptor and Deinonychus in anatomy.  It was initially classified as a "saurornithoidid" (troodontid).  Its name gets tossed around a lot (most velociraptorine-like teeth from the Late Cretaceous of North America get stuck here for lack of anything better to do with them), but it's in bad need of revision.
S. robustus Sullivan, 2006 middle late Campanian (LK) of New Mexico Uh, S. robustus is more robust than the type species...
It is based on a frontal, with teeth and a pedal ungual referred to it. 

Dromaeosaurinae:

Taxon or Taxa: Time/Place: Comments:
Achillobator giganticus Perle, Norell, and Clark, 1999 ?Santonian (LK) of Mongolia Achillobator is a new large dromaeosaurid (femur 50 cm in length, possibly about 3 times larger than Deinonychus in all).  Known from a maxilla, hindlimbs, pelvis, and caudals, it has a variety of unusual features for a dromaeosaurid, including pubes with their front ends lengthened and deep upper jaws.  It has been suggested that this animal was close to Dromaeosaurus.
Dromaeosaurus albertensis Matthew and Brown, 1922 late middle-early late Campanian (LK) of Alberta and Montana Enigmatic until the description of Deinonychus cleared things up, this animal is based on a partial skull and foot, and for a time was considered a small relative to the tyrannosaurids.  Its "killer claw" is somewhat less developed than in other members of this family, and it is supposed this taxon used its teeth for killing as much as its claws.
Utahraptor ostrommaysorum Kirkland, Gaston, and Burge, 1993 Barremian-early Aptian (EK) of Utah A contemporary of the large polacanthid Gastonia, Utahraptor is the largest known official dromaeosaurid.  Several individuals are known from partial remains, but the taxon as a whole is not yet particularly well known.  It may have been close to the large Mongolian dromaeosaurid Achillobator, but is not really all that well known yet.

Velociraptorinae: 

Taxon or Taxa: Time/Place: Comments:
Adasaurus mongoliensis Barsbold, 1983 early Maastrichtian (LK) of Mongolia Adasaurus is based on a partial skeleton of an old individual that includes both a pelvis with the bird condition (pubis pointing backward) and a foot with a hyperextendable second claw (albeit probably less powerful than the "killer claw" of most dromaeosaurids).
Itemirus medullaris Kurzanov, 1976 late Turonian (LK) of Uzbekistan Itemirus is based on an unusual braincase that shows similarities to both tyrannosaurids and dromaeosaurids, but new research puts it in the dromie camp.
Tsaagan mangas Norell, Clark, Turner, Makovicky, Barsbold, and Rowe, 2006 late Campanian (LK) of Mongolia A contemporary in geological formation to Velociraptor, Tsaagan (full binomial is Mongolian [albeit misspelled; should be Tsagaan] for "white monster") is based on a cervical series and skull.
Velociraptor: Osborn, 1924 V. mongoliensis (type) Osborn, 1924 late Campanian (LK) of Mongolia and China Best known from the "fighting" specimen, where a virtually complete skeleton was enmeshed in combat with a Protoceratops, Velociraptor is a smallish, gracile dromaeosaurid with a narrow muzzle and a degree of binocular vision.  A great deal of good skull and skeletal remains are known.
Apparent quill nodes are now known for the arm, which strongly indicates the darn inconsiderate things had big arm feathers after all.  This puts a crimp in my style, as large feathers are outside of my limited artistic range.
Recently-named second species V. osmolskae is based on maxillae and a lacrimal from Inner Mongolia.
V. osmolskae Godefroit, Currie, Li Hong, Shang Chang Yong, and Dong Zhiming, 2008 late Campanian (LK) of China

 

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