[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Dromaeosaurs most efficient (meanest) hunters



Subj:   Re: Dromaeosaurs most efficient (meanest) hunters
Date:   98-02-17 02:38:30 EST
From:   Wile E 81
To:     Pieter.Depuydt@rug.ac.be

In a message dated 98-02-16 06:28:28 EST, you write:

<< I'd like to join in questioning what exactly makes people (and 
 especially the authors of children/popular books) state that 
 dromeaosaurs were "the most efficient or deadly predators dinosaurs 
 ever evolved" and so on, and in fact I'm getting tired of it.
 
 In fact, every predator of which fossils are found undoubtedly was 
 very efficient in what it was doing for its living in its habitat. 
 From the Cambrian anomalocarids, the Silurian eurypterids, the 
 Devonian arthrodires, the Carboniferous loxommatids, the Permian 
 gorgonopians, to the La Brea smilodons ... each time and place saw 
 its most efficient predators, extremely well suited for preying on 
 the creatures it had coevolved with. The very existence of a predator 
 in the fossil record proves its efficiency as such.
 Or otherwise stated, each predator is the most efficient killer for 
 the particular animal which serves as its main dinner.
 On the other hand, heavy specialization to preying on a particular 
 kind of animal (for example development of extreme canines and heavy 
 shoulder muscles, plus size increase in Smilodon, probably in 
 adaptation to predation of the Pleistocene megaherbivores) makes the 
 predator more dependent on its preferred prey and more 
 prone to extinction. More generalist carnivory (and even 
 omnivory) might be more efficient in the long run.
 (efficiency in the sense of getting more offspring, surviving as a 
 species (or giving rise to new species by anagenesis or radiation) 
 for a longer time and in a broader geographical or ecological 
 range etc...)
 
 To go back to where I started from, when I would be forced 
 to vote for the most efficient dinosaur predator (and thus forgetting 
 for a while what I just stated) I would choose the blackbird, the 
 thrush and the crow, rather than the dromaeosaur.
 
 (back to lurking)
 
 Pieter Depuydt >>


<< I think it harkens back to the day John Ostrom noticed that most of the
 characteristics of Deinonychus were those of a highly active animal,
 seemingly more adapted (or specialized) for speed than other dinosaurs
 found prior to it.
 
 But that's just my guess, you understand.
 
 -Betty Cunningham
  >>

yes 
I know that is the assumption  (regardless of the fact that I don' know how to
spell Dromaeosaur Ive been spelling dromeosaur)
 I believe that dromaeosaurs were faster and more agile than a Tyrannosaur for
instance. But how would that make it a more effective hunter as it has been
stated in countless books and documentaries ( it seems jurassic park syndrome
has popularized this view). Hunters have an arsenal of evolutionary tactics it
uses to gain an advantage over its prey that ensure their survival. Speed
gives cheetahs an advantage during pursuit but due to the body type it must
maintain to achieve those speeds  it limits the size of the prey it may
capture, not to mention the limitations on the energy it expends. A lion on
the other hand uses  size,cooperation,and ambush tactics to take down animals
much larger than itself, but lacks the ability to out run faster prey. Plus
they both use unique strategies  as a means to an end. The point being that
dromeosaurs and tyrannosaurs are two evolutionarily diverse animals that have
chosen an alternate means to survival of which they are both successful. Why
then are dromaeosaurs considered better suited for hunting. What makes an
animal better suited for anything if they are both successful at what they do
to survive?
 I suppose you would have to measure each animals success rate and compare but
we will never have such data on "these" animals.

Pieter has expanded this argument beyond my limited scope of tyrrannosaurs and
dromaeosaurs, this just proves the point even further.  
Personally i feel the most efficient hunter are the ones who's specializations
(being physical, social, or even dietary) give it the least limitations on the
prey It may capture.

Newly revised 
Dinosaur Illustration pages 
http://members.aol.com/WileE81/index.html