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4

They are called Nutrient Foramen which are innervation of blood vessels and nerves, you see the same thing in reptile and bird skulls (mammals tent to pack it all into one or two large openings). They feed blood vessels and nerves to the gums, lips, and face. Dinosaurs do seem to have more of them, but size making them more noticable is also a factor. The ...


4

Radically different body shapes and sizes represent overall phenotype. Overall phenotype was used briefly in the 1960s and 1970s for species identification under a statistical distance method called "phenetics". However, phenetics has been rejected as a valid method of species identification. Similarly, although ecologists widely use the Biological Species ...


3

Yes, the study was peer reviewed and published less than a month ago (Dec 18, 2017) in PNAS, among the most prestigious journals in science by qualified experts. They could be wrong of course, like all science. But there is no reason I can see to doubt their work.


3

Disclaimer I was unaware of 2-9-3, but performed a simple internet search which brought up a an open-access paper from 2001 refuting the claim, and nothing more recent, suggesting that the refutation was valid. I mention this both to make it clear that although, like the poster, I am not an expert in the topic one can get considerable mileage through ...


2

there are actually more than one process, but in the case of high detail wood fossils the process is the slow filling in of all the spaces in the wood (filled with water in life) with dissolved minerals from the groundwater. this is called permineralization. Of course this only works is the wood is buried so it cannot rot while this is happening. Since ...


2

Via: https://en.wikipedia.org/wiki/Carbon-13#Uses_in_science Due to differential uptake in plants as well as marine carbonates of 13C, it is possible to use these isotopic signatures in earth science. Biological processes preferentially take up the lower mass isotope through kinetic fractionation. Via: https://en.wikipedia.org/wiki/Kinetic_fractionation ...


1

First, the example you give is unusual in that molecular dating analysis should be calibrated with fossils to set minimum ages. If Ecrobia grimmi exists in the fossil record, then no proper molecular analysis would estimate them to be younger than those fossils. There are two main causes of discrepancies between fossil and molecular dating. For fossils you ...


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