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


It is interesting how people often become strongly opinionated about certain
aspects of dinosaur biology and their expression in the media despite the
current lack of a means of testing their assertions. The ongoing discussion
on illustrating dinosaur hunting techniques is an example. 

One thing that working on BEYOND HUMANITY reinforced in my mind is how little
we yet understand about how brain size correlates with degree of social
interaction. For instance, how much brain power does it take to live in a
complex society that includes royalty, agriculture, slave holding, warfare
via coordinated armies, and architecture including air conditioning. The
answer is not much since ants, bees, and termites with just a few hundred
thousand neurons in each individual do these things! 

To a fair extent socialization is more a function of mobility via aerobic
capacity than of mental development. In the oceans bradymetabolic fish can be
highly social because it costs them so little to efficiently swim in schools.
Social insects either operate over short ranges, or in the case of bees are
flying endotherms. On land the high cost of locomotion prevents low aerobic
capacity reptiles from moving about in organized herds, or hunting in
coordinated packs. 

Although it is true that dinosaurs had smaller brains than mammals, it is
also true that they filled roles today occupied by mammals, and very probably
had aerobic capacities higher than observed in reptiles. It is therefore not
surprising that bonebeds, other fossil associations and trackways apparently
show that predaceous and herbivorous dinosaurs sometimes moving together in
groups at walking speeds not sustainable by reptiles. 

It is therefore quite possible that some theropods sometimes hunted in
groups. Just how sophisticated were their tactics cannot be assessed with the
current data. It is probable that dinosaur behavior was more stereotyped than
in bigger brained mammals, but the example of insects suggests that dinosaur
hunting may still have been a fairly sophisticated affair in some cases.

The observation that because emus are not all that bright that the same must
have been true of advanced theropods with similar sized brains is not
particularly important. Ratites are herbivores. So are ungulates, which are
generally considered not as bright as carnivores even though brain size is
similar in the two groups (contrary to the popular impression). It is just
that herbivores dedicate a large portion of their neurons and synapses to
doing seemingly dull things like finding the best plants, remembering which
they are, and which are palatable and which are not. Predators dedicate their
brains to seemingly more interesting matters such as how to best open the
guts of their prey. Although dromaeosaurs were not able to work locks they
had never seen before or devilishly outsmart a heavily armed Australian bush
hunter, they may have been smart enough to work together in some form of

Perhaps our knowledge base will eventually expand enough to either confirm or
falsify social hunting among dinosaurs, or even tell which theropods were
anti-social or otherwise. Until then dinosaur artists are free to pretty much
do what they like. Note that showing a group of theropods attacking a herd of
dinosaurs does not mean that the artist is saying that the dinosaurs are
thinking at mammalian levels. Unless the artist includes caption ballons with
the restored 
thoughts of the dinosaurs, then all that the picture shows is a group of
theropods assaulting a group of herbivores. The level of thinking involved is
at best difficult to indicate. 

Nor is the burden of proof on those who wish to show dinosaurs hunting in
packs. Dinosaurs are too different from reptiles to assume they had similarly
limited socialization unless demonstrated otherwise, or vice-versa.
Therefore, dinoartists can illustrate a theropod hunting on its own, or show
a pack of them ripping apart some hapless victim, its flesh being eaten while
it is still alive (hyenas and wild dogs often start dining before the prey is
dead). Have fun.