[_ Old Earth _] PALEONTOLOGISTS SOLVE A PUZZLE WITH A NEW FOSSIL

[Barbarian]

Long-sought Fossil Mammal With Transitional Middle Ear Found
Paleontologists from the American Museum of Natural History and the Chinese Academy of Sciences announce the discovery of Liaoconodon hui, a complete fossil mammal from the Mesozoic found in China that includes the long-sought transitional middle ear. The specimen shows the bones associated with hearing in mammals - the malleus, incus, and ectotympanic- decoupled from the lower jaw, as had been predicted, but held in place by an ossified cartilage that rested in a groove on the lower jaw. The new research, published in Nature this week, also suggests that the middle ear evolved at least twice in mammals, for monotremes and for the marsupial-placental group.

"People have been looking for this specimen for over 150 years since noticing a puzzling groove on the lower jaw of some early mammals, " says Jin Meng, curator in the Division of Paleontology at the Museum and first author of the paper. "Now we have cartilage with ear bones attached, the first clear paleontological evidence showing relationships between the lower jaw and middle ear."

Mammals - the group of animals that includes egg-laying monotremes like the platypus, marsupials like the opossum, and placentals like mice and whales - are loosely united by a suite of characteristics, including the middle ear ossicles. The mammalian middle ear, or the area just inside the ear drum, is ringed in shape and includes three bones, two of which are found in the joint of the lower jaw of living reptiles. This means that during the evolutionary shift from the group that includes lizards, crocodilians, and dinosaurs to mammals, the quadrate and articular plus prearticular bones separated from the posterior lower jaw and became associated with hearing as the incus and malleus.

The transition from reptiles to mammals has long been an open question, although studies of developing embryos have linked reptilian bones of the lower jaw joint to mammalian middle ear bones. Previously discovered fossils have filled in parts of the mammalian middle-ear puzzle. An early mammal, Morganucodon that dates to about 200 million years ago, has bones more akin to a reptilian jaw joint but with a reduction in these bones, which functioned for both hearing and chewing. Other fossils described within the last decade have expanded information about early mammals-finding, for example, that ossified cartilage still connected to the groove was common on the lower jaws of early mammals. But these fossils did not include the bones of the middle ear.

The new fossil described this week, Liaoconodon hui, fills the gap in knowledge between the basal, early mammaliaforms likeMorganucodon, where the middle ear bones are part of the mandible and the definitive middle ear of living and fossil mammals.
http://www.amnh.org/our-research/sc...sil-mammal-with-transitional-middle-ear-found

 

[brother Paul]

Why should development, or even variety, within mammalia seem odd or surprising?

 

[Barbarian]

Why should development, or even variety, within mammalia seem odd or surprising?

Actually, Morganucodon isn't a mammal. It has the reptilian ear and jaw structure. Mammals have single bone in the lower jaw, and three bones in the middle ear. Morganucodon is reptilian in these features. It's almost certainly not ancestral to the three lines of mammals (eutherian, marsupial, monotreme). Like Archaeopteryx, Monocodon is halfway between two different classes of animals.

The latest find ties it down, showing how the transition happened during the time the advanced cynodonts evolved into mammals.

 

[Barbarian]

To put a finer point on it, Morganucodon is a reptile, in the same sense that a dinosaur is a reptile. It retains enough reptillian characteristics to be so classified, but it also has a large number of mammalian characteristics. As Darwin pointed out, evolution will always make neat classifications impossible.

 

[brother Paul]

And why should some anatomical similarities be a surprise? when because of such similarities one automatically assumes one becoming another that also is a non-sequitur. One does not necessitate the other! Birds have wings and bats have wings so what...

 

[Barbarian]

And why should some anatomical similarities be a surprise?

Hardly a surprise. The precise orientation of the jaw and ear bones had been predicted based on the transitionals already in evidence. So this is merely further confirmation of the evolution of mammals from thecodont reptiles. And it's not just the anatomical data. We can see it in embryos as well. In the page linked below, notice that the stapes and incus in the Didelphis (opossum) embryo has precisely the same form as in Sinoconodon, a thecodont reptile. Evolutionary development explains why this is so; we don't become reptiles in utero, but our development is advanced from things that went on before. This evidence is completely incomprehensible to creationism, but makes perfect sense if mammals evolved from reptiles.

when because of such similarities one automatically assumes one becoming another that also is a non-sequitur. One does not necessitate the other! Birds have wings and bats have wings so what...

You are confusing homology with analogy. Bird wings and bat wings are structurally quite different, using different tissues for airfoils and generation of force. The remarkable thing is, we have the jaws of so many transitional mammal-like reptiles, that the evolution of the mammalian jaw and ear is very well documented.

Turns out, there's genetic evidence for this, as well:
http://www.sciencedaily.com/releases/2015/04/150422084915.htm

 

[Barbarian]

Turns out, we see this evidence in the platypus embryo as well.

http://www.geol.umd.edu/~jmerck/honr219d/images/l17/morganucodon.jpg

 

[brother Paul]

nice art work...

 

[Barbarian]

nice art work...

Indeed. When someone shows me this (in the embyro of an opossum) it was a moment of revelation for me. Here, in a mammal, was a reptilian jaw, almost identical to jaws of advanced therapsid reptiles.

Takes a huge amount of evasion to deny what that means.

I probably should have told you that these smaller jaw bones had always been part of the hearing sense. Reptiles often put their jaw to the ground, to pick up sound. The vibrations are passed on to the ear, via the angular and articular bones to the stapes. (that's what the incus and malleus are called in reptiles) In a reptilian ear, only the stapes is actually in the middle ear.

So the bones didn't really change function when Meckel's cartilage was lost and they only retained their connection to the stapes. They just weren't attached to the lower jaw, anymore.

 

[brother Paul]

Liaoconodon hui, a complete fossil mammal from the Mesozoic found in China that includes the long-sought transitional middle ear

Duh! Think about it? Where are the earlier MAMLLIAN fossils of the same creature that lack the inner ear?

They say the three cones in the mammal fossils and only two in “some living reptiles” MEANS (so this is just an opinion) the fairy tale that follows, also

Calling Morganucodon a mammal was from YOUR camp not me. So don’t try to act as if you are correcting me…..they write “An early mammal, Morganucodon that dates to about 200 million years ago….I just happen to agree with them on this point. These fossils are just a crushed early form of rodent.

Believed by your scientists to be a FOSSIL MAMMAL

So the facts are there are these earlier MAMALS then this one, and finally later LIVING MAMMALS

Again I say…DUH!

Now some are saying this demonstrates that reptiles transitioned to mammals…..AH-HAH, HAH, HAH, HAH….AH, HUH, HUH< HUH!!!!!!!

Wolves hiding behind their sheepskins nothing more….now hundreds will bombard the internet and the journals with interpretive spins finding any little straw to clutch on to can be used to APPEAR to support their replacement myth…the pro-EB journals will publish many of them and reject any that question or oppose…and viola’ folks like you are convinced….

When someone shows me this (in the embyro of an opossum) it was a moment of revelation for me. Here, in a mammal, was a reptilian jaw, almost identical to jaws of advanced therapsid reptiles.

Takes a huge amount of evasion to deny what that means.

But apparently it isn't hard for people with an agenda to make it appear to mean something it does not....so first off seeing thew ancient ANCESTOR has the developed middle ear jaw and this MODERN relative DOES NOT....it finally proves DE-volution....AH-HAH, HAH, HAH...time to think

“But there’s genetic evidence!!!” Not really. Just because some portions of some mammalian genome share sections in common with some reptilian, avian, or fish genomes does NOT equal one becoming the other….we all share common material that separates us from plants but also share sections with plants…so animals evolved from plants, right? And don’t forget that DEAD the rocks and soil actually BACAME the plants all by itself over billions of years and oh yes the whole complex array of matter/energy….by itself of itself over trillions…..AH-HAH, HAH, HAH….AH, HUH, HUH!!!!!!!

 

[brother Paul]

What's the use in using reason???? I quit.....talk among your self

 

[Barbarian]

Liaoconodon hui, a complete fossil mammal from the Mesozoic found in China that includes the long-sought transitional middle ear

Duh! Think about it? Where are the earlier MAMLLIAN fossils of the same creature that lack the inner ear?

None of them lack an inner ear. Even base tetrapods like amphibians have those. If you mean "middle ear", even fish have both a middle and inner ear. Like salamanders and reptiles, fish only have a stapes.

They say the three cones in the mammal fossils and only two in “some living reptiles” MEANS (so this is just an opinion) the fairy tale that follows, also

As you see, the predicted transitional form was recently found. So there's a complete series of transitionals from the reptillian form to the mammalian form. Precisely what evolutionary theory predicted, but completely incomprehensible to creationism.

Calling Morganucodon a mammal was from YOUR camp not me.

As we discussed earlier, evolution means that the dividing line between major groups will be difficult to determine.
Table 6: A list of groups branching out from the line leading to Morganucodon ("reptilian" side). Morganucodon is often considered "first mammal".
http://www.rmki.kfki.hu/~lukacs/adelobasil.html

So don’t try to act as if you are correcting me…..they write “An early mammal, Morganucodon that dates to about 200 million years ago….I just happen to agree with them on this point. These fossils are just a crushed early form of rodent.

No. "Rodent" doesn't mean "small mammal." Rodents are highly evolved mammals which have numerous features not found in this transitional form.

Barbarian obeserves:
When someone shows me this (in the embyro of an opossum) it was a moment of revelation for me. Here, in a mammal, was a reptilian jaw, almost identical to jaws of advanced therapsid reptiles.

Takes a huge amount of evasion to deny what that means.

But apparently it isn't hard for people with an agenda to make it appear to mean something it does not....so first off seeing thew ancient ANCESTOR has the developed middle ear jaw and this MODERN relative DOES NOT....it finally proves DE-volution....AH-HAH, HAH, HAH...time to think

As I said, it was in an embryo. So later on, the reptilian form changes gradually into the mammalian form in the adult animal.

“But there’s genetic evidence!!!”

Yep. The same genes that make jawbones in reptiles make the auditory bones in mammals. Which confirms the evidence from many mammal-like reptiles, embryological data, and so on. And we know this indicates common descent, because it works on organisms of known descent.

 

[Barbarian]

What's the use in using reason????

It lets you be open to evidence.

 

[brother Paul]

I love evidence. I rely on it. What I question is the assumption based conclusions via interpreting the evidence FROM the hypothesis...

 

[Barbarian]

I love evidence.

I'm just noting the evidence from many different sources, confirms the predicted transition from reptiles to mammals. That the predicted transitionals were found is powerful confirmation of anatomical, embryological, and genetic evidence.

What I question is the assumption based conclusions via interpreting the evidence FROM the hypothesis...

Science works by inferences from evidence, as you see in this case. That the inferences were confirmed by the new transitional is further confirmation that the theory is correct.

 

[turnorburn]

Actually, Morganucodon isn't a mammal. It has the reptilian ear and jaw structure. Mammals have single bone in the lower jaw, and three bones in the middle ear. Morganucodon is reptilian in these features. It's almost certainly not ancestral to the three lines of mammals (eutherian, marsupial, monotreme). Like Archaeopteryx, Monocodon is halfway between two different classes of animals.

The latest find ties it down, showing how the transition happened during the time the advanced cynodonts evolved into mammals.

Creatures don't evolve Jesus speaks them into existence..

 

[Barbarian]

Creatures don't evolve

Sorry, that's been directly observed to happen.

Jesus speaks them into existence..

Are you a creature? I don't think He spoke you into existence. Like all the rest, He used nature to make your physical body. Your soul was given directly by Him, and did not evolve as bodies did. God says that the first living things were brought forth from the Earth as He intended.

 

[turnorburn]

He spoke everything into existence like he did with Lazarus' 4 day old decayed body.. water to wine etc..

 

[Barbarian]

The lesson here, isn't that God has to do miracles. A Creator Who can use contingency and necessity alike to do His will has no need to tinker with creation. When He does a miracle, it's not because He needs to. It's to teach us something.

 

[Barbarian]

The stapes, the one middle ear bone found in non-mammals, is homologous (genetically and embryologically) with the hyomandibular in fish. In the earliest jawed fish, it connected the cranium to the rest of the skull. In earlier, jawless fish, it was part of the second gill arch, supporting the opening and gill structure. Later, it formed a connection between jaws and the cranium.

In the earliest tetrapods, as the skull became fused, it lost the support function and only transmitted sound from the jaw to the inner ear.

This process of exaption (a new function for an old structure) is commonly seen in evolution.