HOME PAGE
 Eras of Life
 Dinosaur Evolution
 Feathered Dinosaurs

Species

 Compsognathidae

MYA
   Compsognathus

150

   Sinosauropteryx

130

 Therizinosauroidea
   Beipiaosaurus

130

   Falcarius

125

   Alxasaurus

112

   Erlikosaurus

95

   Therizinosaurus

75

 Oviraptoridae
   Caudipteryx

140

   Insicivosaurus

120

   Avimimus

95

   Chirostenotes

70

   Rinchenia

70

   Nomingia

68

   Oviraptor

67

 Dromaeosauridae
   Microraptor

126

   Deinonychus

120

   Buitreraptor

90

   Unenlagia

90

   Bambiraptor

80

   Atrociraptor

70

   Dromaeosaurus

70

   Velociraptor

67

 Tyrannosauridae
   Dilong

130

 Troodontidae
   Mei long

130

   Sinornithoides

105

   Troodon

 67

 Alvarezsauridae
  Patagonykus 95
  Shuvuuia 80
  Alvarezsaurus 80
  Parvicursor 80
  Mononykus 70
 Aves (birds)
   Protarchaeopteryx

135

   Archaeopteryx

147

  Recent Discoveries
  Juraventor Starki

Information

 Tyrannosaurs
 Weird Dinosaurs
 Prehistoric Sea Monsters
 Pterosaurs
 Sauropods

 

 

Dromaeosauridae
   These small to medium-sized predators were made famous by the movie Jurassic Park, Of course great entertainment value demanded that the movie velociraptors be much larger and smarter than the real thing.  The movie monsters were shown about three times larger than the real thing and velociraptors were certainly not smart enough nor dexterous enough to turn a doorknob.
    All dromaeosaurs did have a pair of retractable sickle-shaped claws on their inside toes (the second toe officially, counting from the inside of the foot outwards). They were held off the ground to keep them sharp, and were probably never clicked against the ground, as seen in the kitchen scene in Jurassic Park. However a dromaeosaur's main weapons were the sharp slashing claws on its hands, which along with the teeth probably did most of the damage to prey. The foot claws were probably used for gripping onto the backs of large prey, and to deliver the final fatal blows between the ribs or across the stomach. Their curvature is also reminiscent of the beaks of modern predatory birds (true raptors), so perhaps the foot claws were used to tear pieces out of a carcass.
    The dromaeosaurs are a group of fascinating creatures. They are commonly referred to as the "raptors,"  but this is not a technical term favored by scientists to describe these predatory dinosaurs as the scientific term refers to modern day birds of prey, which include the eagles and hawks.  Scientists refer to the dinosaurs by the name of the clade, which is Dromaeosauridae, or the term "Dromaeosaurs."
    Dromaeosaurs are a small clade of theropod dinosaurs which exhibit some highly derived characteristics that they all share.  They had excellent eyesight that permitted them to see distant prey.  They ran on legs and had a stiffened tail that probably functioned as a dynamic stabilizer.  They were fast and agile. They had large grasping manus (hands), with a well-developed slashing talon on their second pedal phalanx (toe).  They had muscular and toothy jaws and large brains for their size.  In short, there were smart, quick and very lethal killing machines. 
   The dromaeosaurs were the most birdlike of all dinosaurs.  Of special interest is their forelimbs, which permitted highly flexible seizing, great for grabbing prey.  It was this ability which may have made possible the "flight stroke."  Feathers are so fragile that they very rarely ever fossilize.  The discovery of Microraptor in 2000 was a major milestone in determining the relationship between dinosaurs and birds.  The little fellow was covered with feathers and is considered the American version of Archaeopteryx.  Although feathers have not been found on later dromaeosaurs, scientists are confident that they had them, as they descended from Microraptor.  Many believe that modern birds and Dromaeosaurs shared a common ancestor sometime in the Jurassic period; Dromaeosauridae is thus termed the sister group of the clade Aves (birds). It may even be that the ancestry of birds lies within this group, which would make them dromaeosaurs too, but this has not yet been  established. 
   Numerous unnamed and indeterminate dromaeosaurids are known.  A few other species are named below.
Microraptor gui - 126 MYA
China - 16 inches long
   This exquisite little fellow was covered with feathers and has been called one of the most-bird like dinosaurs ever known.  Many paleontologists believe it may play a key role in proving once and for all that birds evolved from small meat-eating dinosaurs.
Deinonychus antirrhopus - 120 MYA
Montana, USA.  10 feet long.
   Deinonychus was a fast and vicious hunter. Its name means "terrible claw," and it was given this name because of the large, retractable hunting claw on each of its feet. Like its cousin, the Velociraptor, it used this claw to tear into the flesh of the dinosaurs it hunted.

Buitreraptor gonzalezorum  - 90 MYA
Argentina. 2 feet long
This 2005 discovery in the Southern Hemisphere confirms that dinosaurs were more widely dispersed around the world than previously thought. Scientists now think that dromaeosaurs date back to Jurassic times, when all the continents were much closer together. It is possible that they originated on the ancient continent Laurasia in the north, and migrated to southern Gondwana later.

 
Unenlagia comahuensis - 90 MYA
Argentina  10 feet long.
   Unenlagia is the most bird-like dinosaur found so far - it even had arms that were designed so they could flap like a bird's wings! However, this dinosaur was much too large to fly, but it clearly shows how some dinosaurs were evolving to look and act like modern birds.
Bambiraptor feinbergorum - 80 MYA
Montana, USA. 3 feet long.
   Bambiraptor is one of the most important fossils found in North America. This little bird-like dinosaur was a very quick hunter, and it may have been an important step in dinosaurs' evolution into birds. Bambiraptor is considered by many to be the North American version of Archaeopteryx.

Atrociraptor marshalli
This is a dromaeosaurid dinosaur species from the Upper Cretaceous of Alberta, Canada. The type (and only) specimen was discovered in the Horseshoe Canyon Formation, near Drumheller, Alberta. It had a relatively short, massive skull with slender lower jaws and long, highly curved teeth (the rest of the skeleton is unknown).
Dromaeosaurus albertensis - 70 MYA
Alberta, Canada.  6 feet long
   Dromaeosaurus was the original raptor. It was a small, vicious hunter that had a mouth full of serrated, razor-sharp teeth and a sharp, hooked claw on each foot that it used to clamp down on its victims.  The first and only good Dromaeosaurus remains were found by Barnum Brown on the south bank of the Red Deer River in 1914.
Velociraptor mongoliensis - 67 MYA
Mongolia, China.  6 feet long
   Velociraptor was made famous by the movie "Jurassic Park."  However the movie dinosaur was greatly exaggerated.  The real Velociraptor was  much smaller than shown in the film and was smart enough nor dexterous enough to open doors. Still, pound for pound, Velociraptor was a very effective killing machine!
 

Other Species

    Dromaeosaurs have been recently found in Argentina, Denmark, and other places.  Some were about the size of the Jurassic Park villains, and some were even larger!
  Achillobator giganticus (Perle, Norell, and Clark, 1999)
Means "Achilles Hero" Pronounced: "a-Kill-o-ba-tor"
Length: 17 ft. (5 meters) Weight: unknown
Mongolia, China.  Late Cretaceous - 85 MYA
   Achillobator was a giant raptor dinosaur that was discovered in 1999 and scientists are still studying this huge meat-eater. This dinosaur was similar in size to the North American Utahraptor and was probably one of the most vicious hunters of its time. It has made scientists rethink their ideas about the raptor family in Asia.  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
  
Further study is needed to firmly assign Achillobator to the dromaeosaur family. Its initial assignment to this group is based on a number of shared characteristics, but these findings are preliminary.
  Adasaurus mongoliensis (Barsbold, 1983)
Means: "Ada Lizard"  Pronounced: "A-dah-Sore-us"
Length: 6 feet (2 m).  Weight: 33 pounds (15 kilos)
Mongolia, China.  Late Cretaceous - 75 MYA
    Adasaurus was a small, meat-eating dinosaur that was very lightweight and had many bird-like features. It is considered to be the closest non-avian relatives of the Archaeopteryx.It 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).  Scientists believe that it had feathers.
    This small dinosaur adds fuel to the ever-growing debate surrounding dinosaurs and birds. Adasaurus has been described as being extremely similar to Archaeopteryx. It has enough of the dromaeosaur characteristics to be placed in that family too, but the overall view of those types of raptors is evolving into their being referred to as bird-like dinosaurs, complete with feathers. Eventually, some members of the family may be reclassified as birds instead of dinosaurs.
  Atrociraptor marshalli  (Currie and Varricchio, 2004)
Means "Savage Raptor." 
   Discovered in 2004 and described in the book, Feathered Dragons.
It had a relatively short, massive skull with slender lower jaws and long, highly curved teeth (the rest of the skeleton is unknown). Similar teeth are found in the Upper Cretaceous Lance Formation. Atrociraptor seems to be most similar to Deinonychus.
  Dromaeosauroides bornholmensis (Christiansen and Bonde, 2003)
ate 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).
  Neuquenraptor argentinus   (Novas and Pol, 2005)
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 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).
  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 have been reassigned to the somewhat better known ornithischian Echinodon.  The remains left behind, particularly the type, a dentary fragment with teeth, appear to pertain to a dromaeosaurid.
  Pyroraptor olympius - (Allain and Taquet, 2000)
Name Means: "Fire Raider"  Pronounced: Pie-row-Rap-tore
Length: unknown (small).  Weight: unknown
France.  Late Cretaceous - 76 MYA
     Pyroraptor is the first positively identified member of the raptor family found in Europe. This was a small, fast hunter that lived near the end of the age of dinosaurs. The specimen is known from only a few bones, but they included the "killer claw" associated with this group. They were enough to give scientists a good idea of what this little dinosaur would have looked like. Some paleontologists believe it would have closely resembled the small, bird-like dinosaurs recently discovered in China. Pyroraptor earned its name because the type material was discovered after a forest fire.  It is based on a with additional remains referred to it.
  Rapator ornitholestoides (von Huene in 1932)
Australia.  Very little information.
Based on a single hand bone from Victoria, Australia, Rapator is a large dinosaur from the middle Cretaceous that has puzzled researchers for decades.
  Saurornitholestes langstoni (Sues, 1978)
late Campanian (LK) of Alberta, ?early Maastrichtian (LK) of New Mexico 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, but it's in bad need of revision.
  Utahraptor kirklandi:
During the filming of the movie Jurassic Park, fragments of a large dromaeosaur skeleton were found in Utah. A study proclaimed that the giant raptor from the movie had been found; this animal seemed to be the perfect size for such a creature.
  Utahraptor ostrommaysorum  (Kirkland, Gaston, and Burge, 1993)
Barremian (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.
  Utahraptor oweni
Means: "Utah Robber"  Pronounced: "U-taw-Rap-tor"
Length: 23 feet (7 m).  Weight: 1 ton (900 kilos)
Utah, USA.  Cretaceous
    When the movie "Jurassic Park" was released, dinosaur fans everywhere complained that director Steven Spielberg had made his movie Velociraptors much larger than they were in real life. In the midst of this controversy, Dr. James Kirkland and paleontology student Rob Gaston unearthed the real-life giant raptor that was shown in the movie - only bigger! Utahraptor was huge, and with its big killing claws, strong arms and hands, and sharp teeth, it was one of the most ferocious killers on the planet.
    One of the most unique aspects that Utahraptor shares with its more famous cousin Velociraptor is that both had a lethal killing claw on each foot. Each inside toe had a large (about 10 inches) hooked claw that was controlled by a strong tendon. This claw was held upward when the animal was walking or running. When it attacked, however, the tendon snapped tight and the claw clamped down with great speed and force, slicing deeply into its victim. Not a very pretty picture, but an effective way to inflict a serious wound.
    Utahraptor is the oldest known, and largest, of the dromaeosaurids. This is interesting as it points to a family that shrunk over time. Its hand claws were proportionally larger than other family members and Dr. Kirkland speculates that its hand claws were probably as important a weapon as the killing claws on its feet. Utahraptor is the subject of a best-selling book by Dr. Robert Bakker. Entitled "Raptor Red," it is currently being developed into a motion picture.