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


Hi Michael,

    Thanks for your note and comments.

    You, again, ask a very interesting question:

    "...Other than protecting against damage to unborn offspring in crushing
its own eggs
what other incentive might there be in creating these measured rings of

    Of course, one could postulate that the neat, radial rings of eggs were
not produced by the egg-laying dinosaur, but are the result of eggs laid
almost vertically in a hole within a softer surround of deliberately
deposited vegetation.  Then, one might speculate that as bacteria became
active in decomposing the supporting vegetation, the vertically oriented
eggs gradually tilted outward and radially.

    This idea has, IMHO, some very serious problems, but I shall describe
only two of the many:  (1) The unevenness of fibrous plant structures and
differential decay rates would have low probability of resulting in such
perfect egg spacing and radiallity as is found in nest after nest; (2) If
the vegetation supporting the eggs deposited in a long-axis-vertical clump
did not disintegrate and allow eggs to spread-out during the incubation
period, outer eggs of the clump would experience warmth for incubation
highly differentially across each egg's surface, and, also, heat would reach
the outer eggs of such a vertical clump very differentially from that
reaching the inner eggs of that clump.

    So, we are left with the idea that the eggs were actually laid in the
rather precise radial positions, but of course, one can only speculate on
the functionality while trying to incorporate any known and possibly
pertinent facts, so here goes by two bits worth -- or 2 cents worth, as the
case may be.  :)

    In carefully going over both the books on dinosaur eggs and babies, I
notice concerning those crater-shaped nests containing at least one neat
ring of eggs (with their long axes radial to the nest center), that the more
pointed end of each egg (presumably the end of the egg that emerged first
from the ova-positing cloaca) points toward the center of the nest.
Conversely, the larger, more rounded end of each egg is oriented toward the
raised nest rim.

    Now, let us contemplate this arrangement and nest shape in the context
of an hypothesized ideal thermal condition for hatching.

    It has been postulated by dinosaur egg/nest researchers (any possibly
based on some fossil evidences) that such nests may have been provided heat
(or even shade when needed) for incubation by the body of a brooding parent
(as in the now famous brooding Oviraptor nests in Mongolia).  Or, in some
cases fossil evidence suggests that decaying plant materials may have been
placed over the eggs for heat (as with some modern birds) and/or for shade
in extreme conditions.

    In either of those heat-for-brooding situations, the ideal situation for
each egg would be for air at appropriate temperature to surround or flow by
each egg equally and evenly (across each eggs surface). In the crater-shaped
nest where radially laid eggs have the large end outward, it seems to me
that the inter-nest heat (whether from a brooding parent or from decomposing
vegetation, or both) would, thereby, reach most all of each egg's surface

    The exception to this?  Of course, it is the outwardly oriented larger
more rounded end of the eggs that would experience heat differentially.  Can
there be a survival reason for this?  Conceivably, because the larger end of
the egg -- if they follow the construction pattern of eggs from modern,
non-avian dinosaurs, aka birds -- is where each egg's AIR CELL is located.
Thus, one might postulate that the resultant bi-polar thermal situation
plays a part in facilitating embryo respiration.

    Well, that's my off-the-top-of-the-head (or should I say nest?)
speculation for now.  Let's sit on it and see if it hatches some more
informed insights.  One or more of our list's informational heavy-weights
may smash this nest of speculation by intelligently 'sitting upon' it.
Let's hear what you think.

    Meantime, Michael, keep posting those concise, thoughtful questions.
Such an inquiring mind is surely a part of what makes you, IMHO, one of the
very best restorers of ancient life that paleo-artistry has ever 'hatched'!

    Ray Stanford