Regarding the tiny pterodactyl.

Scientists have often stated that birds are decendant from reptiles. While this is not considered a true transitional seeing as how it really doesn't have interfamilial characteristics, could this species be where birds and the predecessors have originated. I mean it appears that while definately a reptile it shares not only flight, but a smaller body plan, no teeth, and curved digit morphology .Did it have unicate processes? Did it mention if the curved digits were heterodactyl, anisodactyl, or zygodactyl?

Originally posted by FreezBee

Interesting

above link

Forelimb anatomy indicates that the new bat was capable of powered flight like other Eocene bats, but ear morphology suggests that it lacked their echolocation abilities, supporting a 'flight first' hypothesis for chiropteran evolution.

---

© source where applicable

Wasn't that the existing assumption? I mean, not all bats use echolocation, but all bats fly.

- FreezBee

For more, check out A Hairy Archaeopteryx?.

Originally posted by showmeproof

Regarding the tiny pterodactyl.

Scientists have often stated that birds are decendant from reptiles. While this is not considered a true transitional seeing as how it really doesn't have interfamilial characteristics, could this species be where birds and the predecessors have originated. I mean it appears that while definately a reptile it shares not only flight, but a smaller body plan, no teeth, and curved digit morphology .Did it have unicate processes? Did it mention if the curved digits were heterodactyl, anisodactyl, or zygodactyl?

I'm not bothering to look into this--not that it's not an understandable and superficially-plausible hypothesis--but because my best recollection is that pterodactyls are not even dinosaurs, much less members the specific lineage of theropod dinosaurs from which birds are thought to have sprung.

Thus, however appealing a candidate the curved toes (which, IIRC, australopithecoids like "Lucy" also had, arguably also due to a tree-dwelling lifestlye) and small size may make the li'l pterodactyl for a bird relative, I suspect that none of the rest of the anatomy would jibe in detail.

If I'm wrong on this, I'm sure I'll be corrected!

Originally posted by Genesius

I have a question that surely betrays my ignorance, but no shame no gain, right?

What are curved digits? Does it mean that the bone structure is curved, or that the specimen was discovered with the digits in a curved position?

Is it possible that the digits were somehow curved due to stress? i.e. pressure from the surrounding rock, temperature, etc.

It would be my assumption that the digits were curved in life. That is, that instead of the individual bones having a straight orientation along the, erm, long axis, that they actually had a "wow" in them, like the difference between, oh, a boomerang and a "regular" bat or club...

I'm assuming that the researchers infer the curved-during-life from any number of things, such as the overall preservation of the skeleton, whether other bones in the fossil skeleton--known from comparison to the anatomy of other related specimens to be straight--were also straight here, isolating all the anomalous curves to the toes, whether all the toe digits on both footies had a similar curve, and so forth...

As I said (reading "backwards" up the thread) in a response to a later post, "Lucy" and her relatives are also known to have curved digits, which are also suspected to imply either a "current" (that is, contemporaneous) or past-vestigial tree-dwelling lifestyle. (Of course, such eminent "scientific" organizations as AiG use the presence of the curved digits to push Lucy out of the transitional category and into the "just-another-ape" realm, bleh...)

Since curved-digits have been implicated in tree-dwelling in many otherwise phylogenetically-distinct lineages, I think it's reasonable to assume that the actual paleontologists out there know what they're looking at when they see a convergent-on-tree-dwelling, limb-clutching digit as opposed to when they see a fossilized bone that has been secondarily subjected to a twisting force. Perhaps growth patterns and the like...?

Originally posted by FreezBee

Interesting

above link

Forelimb anatomy indicates that the new bat was capable of powered flight like other Eocene bats, but ear morphology suggests that it lacked their echolocation abilities, supporting a 'flight first' hypothesis for chiropteran evolution.

---

© source where applicable

Wasn't that the existing assumption? I mean, not all bats use echolocation, but all bats fly.

- FreezBee

It seems probable that the earliest bats developed flight skills before well before echolocation. Probably the most telling bit of evidence supporting this contention is that, with the exception of the Rousettus and its relatives, none of the megabats (fruit bats) have echolocation (I guess it isn't that necessary when your "prey" is a fruit).

Originally posted by Cyrus Johnson

For more, check out A Hairy Archaeopteryx?.

Thanks for the link.

Originally posted by rogue06

It seems probable that the earliest bats developed flight skills before well before echolocation. Probably the most telling bit of evidence supporting this contention is that, with the exception of the Rousettus and its relatives, none of the megabats (fruit bats) have echolocation (I guess it isn't that necessary when your "prey" is a fruit).

Not necessary, and perhaps not useful. The microchiroptes catch their prey (insects) in free flight (not sitting on tree trunks :´wink:), while fruits are hanging among foliage, where they are easier spotted using color vision than with echolocation. Not that I know anything much about this, but I would assume it's like that


- FreezBee

Originally posted by Steviepinhead

Nah. The curved tootsies were so the little pteros could cling to the "hawking" bracers of the patriarchs when they went out bird-hunting on dino-back.

That makes as much sense as anything else in this thread. Ya got my vote, pinhead.

And the teeth had been bred out of them, so that when the little pteros knocked the duck or quail or whatever out of the air, they couldn't start munching on the prey before Big Daddy rode up on his deino or allo or whatever to bag the birdies...

Suggestion : write it all up using fancy-sounding, multi-syllable, plenty-of-buzz-words language and submit it to Nature, Smithsonian and Science.
I predict that it'll be published by one of those prestigious "science" organizations (it should fly through peer review -- no pun intended).


Jorge

Originally posted by Jorge

That makes as much sense as anything else in this thread. Ya got my vote, pinhead.




Suggestion : write it all up using fancy-sounding, multi-syllable, plenty-of-buzz-words language and submit it to Nature, Smithsonian and Science.
I predict that it'll be published by one of those prestigious "science" organizations (it should fly through peer review -- no pun intended).


Jorge

Now the thread is official since we have one of Jorge's favorite trademarked content-free responses.

Originally posted by rogue06

Now the thread is official since we have one of Jorge's favorite trademarked content-free responses.

With a smiley.

He forgot the colours though.

Originally posted by Steviepinhead

I'm not bothering to look into this--not that it's not an understandable and superficially-plausible hypothesis--but because my best recollection is that pterodactyls are not even dinosaurs, much less members the specific lineage of theropod dinosaurs from which birds are thought to have sprung.

Thus, however appealing a candidate the curved toes (which, IIRC, australopithecoids like "Lucy" also had, arguably also due to a tree-dwelling lifestlye) and small size may make the li'l pterodactyl for a bird relative, I suspect that none of the rest of the anatomy would jibe in detail.

If I'm wrong on this, I'm sure I'll be corrected!

Pterodactyls are reptiles though and the standing arguement is that birds decended from reptiles. I was merely offering this as a transitional ( like a ancestor of archie) with many gaps between due to the fact their body plan is most like a bird than say a t-rex or a triceratops. It just seems that it would have taken a lot less selective variables to have acted on this body plan.

showmeproof:

Pterodactyls are reptiles though and the standing arguement is that birds decended from reptiles.

Well, no, this is a case where the anatomic details matter. The "standing argument" is NOT simply that birds descended from reptiles (reptiles not even being a monophyletic clade), but that birds descended from dinosaurs, and from a particular lineage of dinosaurs (the threopods) and from particular sub-lineages within that lineage...

The forelimb anatomy of pterodactyls and theropods/birds simply doesn't match up. The ptero wing is based on an extended fourth finger; the bird wing is based on the entire forelimb skeletal assemblage of humerus, radius-ulna, wrist, and hand-finger bones, with the finger bones reduced and fused by comparison with the standard theropod three-finger "plan."

And there's no evidence (of which I am aware, though of course that's no absolute guarantee that it doesn't exist!) that theropod dinosaurs were descended from pterodactyls (though I grant that, at some earlier point, pterodactyls on the one hand and dinos/theropods/birds on the other, shared a common reptilian ancestor).

Getting a little more detailed, Dinosaurs are classified within archosaurs, one of those "reptile" clades. The pterosaurs are also usually placed within archosaurs (though there is considerably more contention here) and, in fact, both dinosauromorpha and pterosauromorpha are placed within the archosauran clade of Ornithodira (but don't let the "ornitho" part of that throw you). Because the dinos and the pteros are clades of equivalent phylogenetic status, none of the individual lineages within either clade can be considered to have descended from the other clade.

Instead, assuming the placement of pteros within Ornithodira is correct (and, while again there's some controversy, that appears to be roughly the mainstream thinking...), then the dinos and the pteros both have an "ornithodiran" common ancestor. But once the dino - ptero "split" occurs, there's no going back... And our little tree-living pterodactyl would at best be a "cousin" of dinos, theros, and birds, and not an ancestor or descendant.

Most of the above is based on Wikipedia articles like "Pterosaur" and "Ornithodira," with some googling about for "theropod forelimb anatomy," "bird wing anatomy," and "pterodactyl wing anatomy."

Thanks for raising an interesting question!

Originally posted by Steviepinhead

showmeproof:

Well, no, this is a case where the anatomic details matter. The "standing argument" is NOT simply that birds descended from reptiles (reptiles not even being a monophyletic clade), but that birds descended from dinosaurs, and from a particular lineage of dinosaurs (the threopods) and from particular sub-lineages within that lineage...

The forelimb anatomy of pterodactyls and theropods/birds simply doesn't match up. The ptero wing is based on an extended fourth finger; the bird wing is based on the entire forelimb skeletal assemblage of humerus, radius-ulna, wrist, and hand-finger bones, with the finger bones reduced and fused by comparison with the standard theropod three-finger "plan."

And there's no evidence (of which I am aware, though of course that's no absolute guarantee that it doesn't exist!) that theropod dinosaurs were descended from pterodactyls (though I grant that, at some earlier point, pterodactyls on the one hand and dinos/theropods/birds on the other, shared a common reptilian ancestor).

Getting a little more detailed, Dinosaurs are classified within archosaurs, one of those "reptile" clades. The pterosaurs are also usually placed within archosaurs (though there is considerably more contention here) and, in fact, both dinosauromorpha and pterosauromorpha are placed within the archosauran clade of Ornithodira (but don't let the "ornitho" part of that throw you). Because the dinos and the pteros are clades of equivalent phylogenetic status, none of the individual lineages within either clade can be considered to have descended from the other clade.

Instead, assuming the placement of pteros within Ornithodira is correct (and, while again there's some controversy, that appears to be roughly the mainstream thinking...), then the dinos and the pteros both have an "ornithodiran" common ancestor. But once the dino - ptero "split" occurs, there's no going back... And our little tree-living pterodactyl would at best be a "cousin" of dinos, theros, and birds, and not an ancestor or descendant.

Most of the above is based on Wikipedia articles like "Pterosaur" and "Ornithodira," with some googling about for "theropod forelimb anatomy," "bird wing anatomy," and "pterodactyl wing anatomy."

Thanks for raising an interesting question!

thanks for providing a detailed answer. I will be the first to admit that I definately don't know my dinosaurs. But I am definately willing to learn..

I guess that would be a key in why any mention of birds, evolution, etc, are absent from the article. Sometimes it is just as important to understand what wasn't said.

The recent discovery of a pair of large carnivorous dinosaurs in the African country of Niger has done much to flesh out what life was probably like 110mya (Cretaceous) in the southern landmass known as Gondwana. While most people are aware of Tyrannosaurus rex, they were exclusive to the northern hemisphere so other carnivores developed, some of which bore little resemblance to T. rex aside from their ferocious appetite for meat. Both were approximately 25’ tall (though one source states that one may have grown up to 40’ long), stood about 7’ tall at the hip and ran quickly on powerful hind legs with the aid of a long tail. They competed for prey with a third creature, which was previously discovered in the mid-90s and which hunted both in and out of the water. But the three massive predators likely divided up the rich spoils based upon how their body structures impacted their hunting capacities.

Paleontologists named one of the newly discovered dinosaurs Kryptops palaios, which means "old hidden face," because of its the horny covering that appears to have covered nearly all of its face. It possessed short, armored jaws with small teeth that seem to be best suited for scavenging carcasses rather than snapping at living prey. Its discoverers describe it as, “a fast, two-legged hyena gnawing and pulling apart a carcass.”

The second new dinosaur was named Eocarcharia dinops, or "fierce-eyed dawn shark," for its razor-sharp blade-like teeth and prominent bony brow which probably gave it a menacing glare and may have been used as a sort of battering ram in contests with rivals while attempting to mate. Unlike Kryptops, its teeth definitely were designed for taking down live prey by severing body parts and tearing out great chunks of flesh. It was probably the primary predator of the group of large carnivores co-existing in Gondwana during the Cretaceous. Eocarcharia and its relatives (called carcharodontosaurids) gave rise to the largest predators on southern continents, matching or exceeding Tyrannosaurus in size.

The previously discovered sail-backed 36-foot long Suchomimus or "crocodile mimic," is the third member of this carnivorous trio, and likely feasted mostly on fish because of its long, narrow snout and hook-like teeth.

These dinosaurs lived at a time when land bridges connected Africa to India and even Antarctica, which was then a temperate home to dinosaurs. In fact, the region they were discovered in is now part of the Sahara Desert but was then a lush forested area. But Africa later became isolated and its dinosaurs followed unique evolutionary paths scientists are just now beginning to uncover. Interestingly, the lead paleontologist of the team that discovered these dinosaurs, University of Chicago paleontologist Paul Sereno, made the following remark that promises even more new finds: “We have not released even half of all that we found there,”



For more information:

http://www.sciencedaily.com/releases...0213193749.htm

http://ap.google.com/article/ALeqM5i...-xRwAD8UQB05G2

http://dsc.discovery.com/news/2008/0...-dinosaur.html

Originally posted by Steviepinhead

I'm not bothering to look into this--not that it's not an understandable and superficially-plausible hypothesis--but because my best recollection is that pterodactyls are not even dinosaurs, much less members the specific lineage of theropod dinosaurs from which birds are thought to have sprung.

Thus, however appealing a candidate the curved toes (which, IIRC, australopithecoids like "Lucy" also had, arguably also due to a tree-dwelling lifestlye) and small size may make the li'l pterodactyl for a bird relative, I suspect that none of the rest of the anatomy would jibe in detail.

If I'm wrong on this, I'm sure I'll be corrected!

Just a note about "Lucy's" curved phalanges... They were midway between straight human fingers and toes and strongly curved ape digits. In fact, you could say they were sort of a transitional feature between an arboreal existence and bipedalism.

Originally posted by rogue06

Just a note about "Lucy's" curved phalanges... They were midway between straight human fingers and toes and strongly curved ape digits. In fact, you could say they were sort of a transitional feature between an arboreal existence and bipedalism.

But was she moving towards bipedalism (a precursor of bicycleism), or was she reclaiming the treetops?

- FreezBee