Period : Early Cretaceous ((Aptian - Albian stages, 121 to 98.9 million years ago )
Location : USA ( Montana, Wyoming and Oklahoma , also probably Maryland )
Length : 3m (11 ft)
Height : 2m (7 ft to head) , 0.87m ( 2.87 ft to hip)
Weight : 73 kg ( 161 lbs)
Introduction :
As the name 'Terrible Claws', Deinonychus is named after its large and terrible claw. Its claw is about 12cm (5 in) in length. Try to imagine when the claw is stab into your stomach, your oargans and blood probably flood outside. With the power of company, the animals are enough to kill large dinosaurs like sauropods and ankylosauridae. What's more? Their teeth is similar to a hook and bore prominent serrations. This is very conveinent for them to cut fresh and bones.Also, their teeth provided the function of cutting fresh alive from their prey. It is definitely a nightmate in the Cretaceuos America.
However, this species of the terrible dinosaur is though to be a very close relative to birds. In the 1960s, when the feathered dromaesaurus still earthed in China. American scientist try to compare the bone of therapod dinosaurs with birds. Finally, they found that Deinonychus skeleton is look like a bird skeleton! So it lead a hypothesis that Deinonychus could be an ancestor or relative of birds. Finally, when the feathered dromaesaurus finally in China, the hypothesis proved to be right. But we still don't know exactly should dromaesaurus be ancestor or relative of birds.
Finally, everyone think that dromaesaurus like deinonychus could run very fast. But according to the recent study. The ratio of foot and tibia is .48, which lesser than Struthiomimus (.68) and modern fleet-footed birds like ostrich (.95). This is proved that they cannot run very fast. But the storter ratio can reduce their stress when jumping and slashing their prey. Personally , I think they will hide in somewhere and wait for their prey and kill.Beside that I dun think they will run and walk all the times but jump like modern spallow is more suitable for them.
Here copy from my blog...
有冇人幫幫手translate to 中文?
Happy New year
Re: 恐爪龍非常聰明，它們成群打獵，跑起來非常迅速。
See the article belows.....
Dromaeosaurids, especially Deinonychus, are often depicted as unusually fast-running animals in the popular media, and Ostrom himself speculated that Deinonychus was fleet-footed in his original description.[17] However, when first described, a complete leg of Deinonychus had not been found, and Ostrom's speculation about the length of the femur (upper leg bone) later proved to have been an overestimate. In a later study, Ostrom noted that the ratio of the femur to the tibia (lower leg bone) is not as important in determining speed as the relative length of the foot and lower leg. In modern, fleet-footed birds like the ostrich, the foot-tibia ratio is .95. In unusually fast-running dinosaurs like Struthiomimus, the ratio is .68, but in Deinonychus, the ratio is .48. Ostrom stated that the "only reasonable conclusion" is that Deinonychus was not particularly fast compared to other dinosaurs, and certainly not as fast as modern flightless birds.[31]
The low foot to lower leg ratio in Deinonychus is due partly to an unusually short metatarsus (upper foot bones). The ratio is actually larger in smaller individuals than in larger ones. Ostrom suggested that the short metatarsus may be related to the function of the sickle claw, and used the fact that it appears to get shorter as individuals aged as support for this. He interpreted all these features – the short second toe with enlarged claw, short metatarsus, etc. – as support for the use of the hind leg as an offensive weapon, where the sickle claw would strike downwards and backwards, and the leg pulled back and down at the same time, slashing and tearing at the prey. Ostrom suggested that the short metatarsus reduced overall stress on the leg bones during such an attack, and interpreted the unusual arrangement of muscle attachments in the Deinonychus leg as support for his idea that a different set of muscles were used in the predatory stroke than in walking or running. Therefore, Ostrom concluded that the legs of Deinonychus represented a balance between running adaptations needed for an agile predator, and stress-reducing features to compensate for its unique foot weapon.[31]
In his 1981 study of Canadian dinosaur footprints, Richard Kool produced rough walking speed estimates based on several track-ways made by different species in the Gething Formation of British Columbia. Kool estimated one of these track-ways, representing the ichnospecies Irenichnites gracilis (which may have been made by Deinonychus), to have a walking speed of 10.1 kilometers per hour (6 miles per hour). http://en.wikipedia.org/wiki/Deinonychus
Deinonychus cannot run as fast as expected because of :
1. Short foot-tibia ratio
2. Relative close pubis and ischium
franco 仔資料又錯了....修改一下