Thoughts on Why Dinosaurs Such as Tyrannosaurus
Rex, i.e., Meraxes Gigas, Have Small Arms and Hands
My Updated and
Complete Reply to a Science Article Posted on Facebook on 07-08-2022 on Why
Dinosaurs with a Similar Body Architecture to That of T-Rex, i.e., Meraxes
Gigas, Have Small Arms and Hands (or biological analogs of hands), cited online
article’s click-on hyperlink at https://abcnews.go.com/Technology/giant-meat-eating-dinosaur-species-discovered-argentina/story?id=86386556&cid=social_fb_abcn
The precise reason that their arms are small can be deduced from looking
at extant bipedal or semi-bipedal species such as humans, (penguins), kangaroos, wallabies,
kangaroo mice, praying mantises (insects
that typically stand on 4 legs, with two others functioning as arms, instead of
6 legs that are the standard for insects), as well as less so the great apes and lesser
apes, respectively of chimps, bonobos, gorillas, orangutans and gibbons,
Barbary apes, as well as the ground-dwelling monkeys of various species of
baboons, which is because they no longer walk and run, as a matter of course,
or characteristically, at all or materially as much on their front limbs, which
were previously strictly legs and feet, when they were four-legged, four-footed
animals, with all limbs, and their attached four feet too then, ground-bound
and propping up and supporting their bodies and body weight. With the freeing
of their once front legs and feet from being ground-bound and weight-bearing
and the repurposing of the front limbs and feet to being characteristically
arms and hands free/d from bearing body weight, or in such a transition as in
the case of the referenced apes and baboons, there would be, over generations
of their descendant posterity, substantial or appreciable bone, muscle-mass and
connective tissue diminishment of or loss for them, in a sense adaptation-related
limited atrophy for them in their new bio-architectural form and usage as arms
and hands or hand analogs. The more characteristically upright standing a
species is in its mobility and awake-state activities, over a numerous critical
number of generations of descendent offspring, the less in appearance and function
its leg-and-feet front limbs would tend to be and the more arm-and-hand
appearing and functioning they would tend to be. The hind legs and feet of the
changed animal species would tend to gain size and bone, muscle and
connective-tissue mass with them taking over the burden and workload of bearing
the weight of the body on their own that is no longer or much less supported by
the front limbs (except in the case of the praying mantis insect, retaining
four legs for standing and holding up the bulk of its body while using its
forelimbs as arms and hands or analogs of them), become or in the state of
transition to arms and hands, or analogs of hands, [as adjuncts] for predation.
In the case of T-rex body-architecture shaped, bipedal dinosaurs with
enormous heads and bodies and small arms and proportional hands or hand analogs
to their arms, because of the giant size of their heads and protruding mouths
and many huge teeth, like hyenas, wolves, dogs, monitor lizards, alligators and
crocodiles of our time, they would both be superlatively efficient bite-attack hunters
and bite fighters as well as protective of their head and the rest of their
body with their greatly larger head, mouth and many such teeth, with the additional
advantage afforded to them with their characteristic upright mobility stature
of panoramic vision over their environments, prey and combatant competitors bound
to the ground with their four legs and four feet attached to their legs, and of
comparatively rapid upper-body, including perhaps independently their head and whole-body swaying, swiveling, bending
forward and back and turning and turnaround ability, as well as the potential
or capability to rapidly hop high and long lengths with both of their bipedal
legs and feet and to kick with a leg and foot, obviating their need for using
their arms for hunting and combat or defense, although their arms and hands or
analogs of hands very well may have been formidable for swatting off and
felling lesser prey and pack or leaping predator-competitor animals with them
for their common prey animals that were
not large dinosaurs, such as lions, tigers, bears, etc., if they existed during
their geological era, or small and modest-sized dinosaurs of their era. Incidentally, lions, tigers, cats of all
kinds in general and bears have dual use front limbs that function as two of
their normal four legs and feet for ground mobility and as a set of two arms
and clawed paws for climbing trees and swatting, mauling, clutching, subduing
and killing prey and other predator-competitor animals. Unlike with male cats, which have retractable
genitalia that are internal until they engage in sexual intercourse, it is
risky and a disadvantage for canines to bipedally stand and locomote upright
because in doing so they would, especially males, expose their externalized
vulnerable reproductive and pain highly susceptible genitalia to assault and
injury or destruction by other attack animals, a disadvantage in upright
stature and locomotion that dinosaurs, predecessors and relatives, if not the progenitors,
of birds, with a T-rex like body architecture, might not have had in their
possibly having had, for males, internal genitals, kept within the cloaca as in
the case of birds, that could, like in male birds, be externalized for
reproductive coitus with females. In
societally primitive humans, clothing, such as a loin cloth or covering at a
minimum, as well as the human weapons of stick or torch wielded fire, knives,
spears and shields could respectively hide, and possibly protect against and
fend off or kill attacker animals before they could attack their genitalia. What the latter have in common with the
referenced primate species is that both of these kinds of animals regularly or
occasionally climb up, about in and down trees and are lineage climbers of and
residents or sojourners in or of trees, which work as an ecological niche in establishing
and maintaining the arms and hands or paws of their putatively once strictly
front legs and feet. The arms and bladed
or clawed hands of T-rex body-like dinosaurs could have been used to push and
poke, or slash, or possibly even stab, other animals, and scrape meat from the bones
of a carcass that they might desire to savor while eating it, and to help them
upright themselves, their bodies, from falls to the ground or from sitting or
reclining related to rest or sleep, as in pushing in a needed direction (on a
side or from side to side and/or below and behind), along with their tails,
against the ground to initiate the uplifting of their bodies, as
well as to help them seat or recline themselves for rest or sleep and to lift and handle their infants and to tussle with and box one another like
kangaroos and wallabies of our age ritualistically do. Their tremendous size and weight insinuate
that their body architecture and type were highly successful in feeding and
prospering themselves in hunting and fighting.
Though their circa 3-foot-long arms might have been as large and
powerful as those of the most powerful grizzly bears of our time, the small
size of their arms relative to their huge dinosaur bodies would make more
biological sense in purposefulness if they attached to penguin-like, bat-like or
great-blue-heron-bird-like, etc., wings on the T-rex dinosaur model scale. I saw a video of a penguin facing down on glacial or snow-covered ground
lift its body upright by pressing its wings forward against that ground.
.
Photos of kangaroos: https://www.istockphoto.com/photos/kangaroo
Photos of wallabies: https://www.istockphoto.com/photos/wallabies
Photos of praying mantises: https://www.istockphoto.com/photos/praying-mantis
Photos
of penguins, https://www.istockphoto.com/search/2/image?phrase=penguins+photos
Photos of winged bats: https://www.istockphoto.com/photos/bat-wing
Photos of great heron birds: https://www.istockphoto.com/photos/bird-of-prey-hunt, https://www.istockphoto.com/photos/bird-catching-fish, https://www.istockphoto.com/photos/grey-heron, https://www.istockphoto.com/photos/Great-Blue-Heron
The cited online
article’s click-on hyperlink is https://abcnews.go.com/Technology/giant-meat-eating-dinosaur-species-discovered-argentina/story?id=86386556&cid=social_fb_abcn
