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Theropod predation, then and now -- some musings



Cuvier -- even Richard Owen when, perhaps, he had one+
with dinner -- believed in the uses of
actualism/actualisme/aktualismus, i.e., inferring
paleoecologies (and form/function complexes) from
ongoing macroevolutionary processes. In a previous
daydream-on-paper on theropod predation, I mentioned
the 1995 paper by Richard Coss and R.O. Goldthwaite,
which is quite interesting. They use actualism to
predict environmental contexts and behavioural
strategies of earlier hominids (Australopithecus,in
particular). Their study group: extant pongids, using
gender differentiations to infer how hominids slept,
foraged, and reacted to predators. They call it
"sexual dinichism". Derived from environmental
contexts connoting  predation threat, the prey over
generations established, so to speak, "memories" with
distinct gender ramifications. Richard Coss,monitoring
playground equipment, has discovered gender
differences of climbing ability and frequency, and,
among adult extant hominids, how the sexes differ in
walking around/near trees during the night.
Extrapolating from this, Richard Coss believes these
paleomemories explain, in part, the gender differences
in precision vis-a-vis reaching and grasping target
objects in complex environments. He is convinced that
female  Australopithecus, like extant female Homo
sapiens, have "a greater number of arboreal
adaptations than larger-bodied males, a finding
suggesting that males were less adept climbers and
spent much more time on the ground than
females....Cognitive evidence for ancestral sexual
dinichism in antipredator behavior is apparent in
preschool children who are asked to climb silhouettes
of trees to seek refuge from a 'lion' and to describe
the spatial location of scary things in their bedrooms
at night".
For me, the question becomes: could it be that female,
feathered theropods were better climbers (and fliers)
than males in protecting offspring etc.? Could flight
have evolved among some of these taxa not to catch
prey, but to avoid becoming prey? In environmentally
stressed region, where population densities of
predators approached levels of prey (thereby causing
extinction events among both), sexual dinichism among
feathered theropods would have created genomic
"memory", behavioural strategies of escaping from, or
avoiding contact with, larger predators (conspecific,
or otherwise). I have no evidence that "racial memory"
exists among hominids or extant dinosaurs. But Richard
Coss's research seems to demonstrate convincingly the
biological patterns of extant taxa may be "genetic"
programmes, repeating paleobehavioural patterns. Thus,
flight among troodontids and dromaeosaurs may have had
multiple causality, and secondary loss of flight
("loss" or "abandonment"?) could be results from loss
of predation threat.

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