Crocodiles Transitional fossil that back in Jurassic time

[shunyadragon]

An important transitional fossil for crocodiles has been found.

Paleontologists have actually found a Jurassic fossil tail, which could be the missing out on web link in the family tree of crocodiles.

[rogue06]

I'm fairly certain that fossils of an ancient crocodilian that was likely completely aquatic with a fish-like tail have been found before. In fact, crocidilians have at various times filled a variety of ecological niches that they don't occupy today. For instance, some ancient species lived in arid environments, some were arboreal, some were bipedal, some had boar-like tusks and some were vegetarian or ate grubs^[1]













1. A cool article about five different types of extinct crocs discovered in 2009 in Niger with such nick-names as "BoarCroc," "DogCrock," "RatCroc," "PancakeCroc," "DuckCrock"

[rogue06]

I'm fairly certain that fossils of an ancient crocodilian that was likely completely aquatic with a fish-like tail have been found before. In fact, crocidilians have at various times filled a variety of ecological niches that they don't occupy today. For instance, some ancient species lived in arid environments, some were arboreal, some were bipedal, some had boar-like tusks and some were vegetarian or ate grubs^[1]






1. A cool article about five different types of extinct crocs discovered in 2009 in Niger with such nick-names as "BoarCroc," "DogCrock," "RatCroc," "PancakeCroc," "DuckCrock"

Yup, in 2007 up in Oregon but it was amphibious although it "was awfully close to being purely aquatic."

Source: Jurassic Crocodile Unearthed in Oregon

Thalattosuchia, a group of crocodilians living during the age of dinosaurs.

The reptile roamed a tropical environment in Asia about 142 to 208 million years ago. Called a ThalattosuchianLiveScience.

Like modern-day crocodilians, the creature sported both land-lubbing and ocean-faring equipment. It had short, stubby legs, which the scientists say would have allowed it to creep easily along the ground and lay eggs.

But the amphibious ThalattosuchiaSource

© Copyright Original Source

[shunyadragon]

Yup, in 2007 up in Oregon but it was amphibious although it "was awfully close to being purely aquatic."

Source: Jurassic Crocodile Unearthed in Oregon

Thalattosuchia, a group of crocodilians living during the age of dinosaurs.

The reptile roamed a tropical environment in Asia about 142 to 208 million years ago. Called a ThalattosuchianLiveScience.

Like modern-day crocodilians, the creature sported both land-lubbing and ocean-faring equipment. It had short, stubby legs, which the scientists say would have allowed it to creep easily along the ground and lay eggs.

But the amphibious ThalattosuchiaSource

© Copyright Original Source

Thank you for the new references!

[rogue06]

Yeah, crocodiles are often listed as being a "living fossil"^[1] which seems strange given just how wildly diverse they were See post #3).













1. Personally I see "living fossil" as being a misnomer much in the same way "missing link" is. It sows confusion and leads to a lot of misunderstandings.Here are two great articles on the topic:

The Rise and Fall of the Living Fossil

The Falsity of Living Fossils

[shunyadragon]

Yeah, crocodiles are often listed as being a "living fossil"^[1] which seems strange given just how wildly diverse they were See post #3).













1. Personally I see "living fossil" as being a misnomer much in the same way "missing link" is. It sows confusion and leads to a lot of misunderstandings.Here are two great articles on the topic:

The Rise and Fall of the Living Fossil

The Falsity of Living Fossils

A side note is I believe that the concept of how species are defined in the past is becoming increasingly unworkable. The more we study the genetics of living animals, genetics of recent extinctions, and fossil remains over the billions of years including the evolution of primate species, species do not evolve to other species. Evolution is more a continuum change, differentiation and branching overtime, and it has become increasingly difficult to define species at any place and time over the history of life over the billions of years. The exception to a certain extent is among the simpler life forms.

The conclusion is you will never 'see' one species evolve into another.

[rogue06]

A side note is I believe that the concept of how species are defined in the past is becoming increasingly unworkable. The more we study the genetics of living animals, genetics of recent extinctions, and fossil remains over the billions of years including the evolution of primate species, species do not evolve to other species. Evolution is more a continuum change, differentiation and branching overtime, and it has become increasingly difficult to define species at any place and time over the history of life over the billions of years. The exception to a certain extent is among the simpler life forms.

Both are correct. It all depends on the context. To clarify: when someone claims that there are absolutely no transitionals it would be absolutely accurate to say that this is false and that there are many examples. On the flip side, when talking about the number of clear, obvious transitionals compared to the number of different fossil creatures found it would be accurate to say there are few transitionals.

You may have noticed that I specified "clear, obvious transitionals." This is because it may be very easy to miss spotting some transitionals in the fossil record because only the most obvious differences can be seen by examining the hard parts (like shells, teeth and bones), which is usually all we have left to examine.
For example, experts are hard pressed to distinguish between a skull from a modern tiger and a skull from a modern lion. While they are both big cats, I think we both can agree that they are very different. And that difference is far more than just outward appearances. Tigers are solitary hunters preferring to strike from ambush. Lions prefer to belong to a pride which usually go out together and run down prey (they are actually unusually social compared to other cats). The male lion rarely backs away from a conflict, whereas a tiger usually will.

Yet, looking at the skulls it takes an expert to tell them apart. IIRC, it is even a bit difficult to distinguish the rest of the body from skeletal remains as well even though tiger are usually stronger in the hind legs and lions usually stronger in the front legs. Lions can run considerably faster than a tigers can.

One other difference is that tigers have larger litters, averaging 2 to 4 cubs whereas lions average 1 to 2, but tigers nurse their cubs nearly twice as long. This isn't something that an examination of bones will reveal^[1]

I imagine it would be even more of a challenge with animals you've never seen alive and the bones of which are often damaged and incomplete. And since most evolution seems to happen in the soft tissues (primarily because there is more of it than hard parts like bone), which are rarely preserved as fossils, it would seem to be highly likely that we've got many, many more transitionals but aren't able to recognize them.

All of this is compounded by a lack of trained paleontologists and taxonomists, for it can take a decade's labor to prepare and analyze the material for just one lineage. Not to mention that the description of fossils has been mostly restricted to professional literature and doesn't get seen by those outside the field (though this is thankfully changing due to the internet). As the fossils that we already have get examined by trained experts we'll surely see many more transitionals emerge from museum back rooms.

The conclusion is you will never 'see' one species evolve into another.

And yet we have repeatedly witnessed speciation take place both in nature and inside the lab. So much so that YECs have abandoned the claim that all species are independently and divinely created and now even rely upon speciation to try to explain how so few animals on Noah's Ark can be responsible for all the diversity of life that we see around us.









1. Another example is that while it is generally agreed that dogs descended from wolves the when and where is difficult to determine due to the difficulties researchers have in distinguishing between wolf remains and dog remains, and why now the answer is being determined by genetics.