Re: Ptero embryo

[Mike Hanson <mhanson54@comcast.net>]

"Well, from the look of the photo it seems a bit "scrambled" compared to

the wonderful illustration above it. So far I can only understand parts
of it. I will be heading toward Washington University this morning to
see if I can access a pdf. In the meantime, if anyone can send me a pdf
[or better yet, I hi-rez jpeg], I'd appreciate it, just in case I run
into some red tape."


Well, just about all embryos found in their eggs are scrambled, take a look at most 
dinosaur eggs. In fact, I think knowing that it is "scrambled" is a sign that 
it is a genuine pterosaur egg.


"Here is a list of inconsistencies I've found between the new embryo and
the 40 or so old "illusion" embryos I've become familiar with. And
remember, inconsistencies are not bad, they're just different."


As you may know, I've always been of the opinion that these "illusion 
embryos" are illusions, so here's my $0.02 on your observations. Just remember, 
they're coming from someone who is rather conservative in their views on the subject.


"1. the embryo is ossified"

In most, if not all oviparous vertebrates the embryo is(at least partially) 
ossified before hatching. Take a look at dinosaur embryos, or even crocodilian 
embryos, the embryos of most other reptiles... Also, knowing that the bones in 
pterosaurs are hollow, even if prolacertiform embryos were not ossified 
pterosaur embryos probably had to have at least partially ossified bones (as 
most ground-nesting birds do), or else their bones would end up collapsing from 
the weight of the body.

"2. the embryo is not with its mother"

Why does it have to be? If it is an egg, as it almost certainly is, there is 
absolutely no need for the mother to be with it. You don't see bird mothers 
flying around with eggs in their mouths, why would the mother have to be with 
it if it were an egg [that fell into a body of water]. I haven't heard of any 
animal mothers going after an egg that fell into a body of water and killing 
themselves as a result. This is far to dependant on your theory that pterosaur 
babies clinged to their mothers, which is also a theory dependant on your 
illusion embryos.
"3. the tibia is much longer than then femur"

That also requires your baby pterosaurs to be real also. Since I don't believe 
they are real I don't find any sort of point in this. I think that the ratio of 
the length of the tibia to that of the femur remained almost the same 
throughout the animal's life (with a few possible slight fluctuations), as it 
does in just about all other animals. I don't think there would be a drastic 
change in the proportions as you seem to suggest.

"4. the sclerotic ring appears to be relatively large in relation to the
skull length"

I think that if anything, this observation supports the idea that this is an 
embryo. Just about all young animals have short skulls and large eyes and I do 
not think pterosaurs would be much different.

"5. if the embryo is a baby Haopterus, the rostrum is much shorter and
rounder than the neonate Haopterus I found [see pterosaurinfo.com]"

First of all, the authors think it is something *similar* to Haopterus, but not 
a Haopterus embryo itself. Second, I think your Haopterus neonate is just 
discoloration and surface features on the matrix. Finally, as stated in 4, a 
short rostrum is a sign of it being a baby.

"6. the teeth are much smaller than I see in other embryos"

Most young animals have small teeth. This is yet another observation that is 
dependant on the existance of these illusion embryos.


All your observations pointing against this being an embryo are extremely 
dependant on your theories on these baby pterosaurs you report, which do not 
exist in my opinion, as they are not more than matrix features, artifacts of 
preservation and preparation and discolorations/stains.


"In addition, the record of Wang and Zhou is not good with regard to
identifying pterosaurs and parts of pterosaurs."


Their record might not be good, but there is no doubt in my mind that this 
is an egg, the embryonic position, the shape of the region of discoloration 
around the embryo that is also contained within a calcreous shell... It is too 
much like an egg to not be one!


"I have a working hypothesis that indicates the Chinese embryo may not be
an embryo at all, but rather a better explanation may be discovered in
the details. I've given a few clues to the working hypothesis above.
I'll let you all know what's cooking when my testing is complete."


Yet again, I don't think it could be anything but an embryo, as I already 
pointed out, considering that it is in a typical embryonic position, there is a 
large amount of discoloration around the specimen resulting from the contents 
of the egg and this discoloration is in an elliptical shape that is contained 
within a calcareous shell! I can't think of too many things other than egg that 
would fit such a description.


"Pterosaur offspring do not have proportionately larger eyes. They have a
tibia shorter than the femur, relatively large feet and a shorter
antebrachium. The rostrum may be shorter. At birth the wing finger may
be relatively longer than that of the parent and folded at every joint.
Long-necked adults have long-necked neonates. The data shows that no
more than two juveniles and two embryos are present, except in breeding
grounds where the matrix may be littered with abandoned babies. As in
bats, offspring clung to the mother, apparently beneath her and oriented
posteriorly. Maternal feeding was necessary until independence, some
time after half the adult size was reached. Rapid maturity equal to the
gestation period is presumed."


I think that a lot of this has now been put to rest with the discovery of 
this pterosaur egg. Also, there is still much that simply doesn't fit in with 
trends seen in the rest of all known vertebrates. All other vertebrates known 
have large eyes and short snouts as juviniles. There is almost never an extreme 
difference in the ratio of the tibia to femur between juviniles and adults. And 
while hands and feet are usually large in juviniles, there is rarely a 
difference in arm proportions between adults and juviniles. And everything 
dealing with viviparity and the young clinging to the mother can be put aside 
since there are TWO pterosaur eggs known to science, one from Liaoning and one 
from Argentina.


"Specimens showing incomplete ossification (e.g. BMNH 37012) appear to be
on the verge of independence. Delayed ossification facilitated the
development of extremely thin-walled hollow bones. Previous associations
of pelvic shape and crest size with gender no longer appear valid
because many mothers and infants ? from <i>Longisquama</i> to the
super-crested nyctosaurs, KJ1 and KJ2 ? had large crests."


I think that delayed ossification could have hindered the developement of 
hollow bones and would have instead produced heavy bones as a result of the 
effect of gravity of the individual (a reverse effect can be seen in humans 
that ave spent long periods of time in space). The hollow bones wound HAVE to 
have been developed within the egg. As for pelvic shape and crest sixe, the 
longisquama neonate seems to be no more than a regular feature in the matrix, 
nothing more. As for the KJ1 and KJ2, both specimens were painted and as a 
result were badly stained, the crests and babies you see are nothing more than 
stains from paint

-------------------------------------

Mike Hanson
Email: mhanson54@comcast.net
Website: http://www.archosauria.org
The Pterosauria: http://www.archosauria.org/pterosauria/
Dinosauricon Art Gallery: http://dino.lm.com/artists/display.php?name=mike