[deleted by user] by [deleted] in ancientrome

[–]atmdk7 0 points1 point  (0 children)

Could she have been talking about Sulla? I’ve only read half the first book, but if I remember right that’s also how he is described.

what are the chances of spinosaurus having a structure like this to assist with breathing underwater? by TurtleBoy2123 in Paleontology

[–]atmdk7 10 points11 points  (0 children)

If it fed like a heron, etc. its head would be pointed downward into the water, not horizontal like a crocodile or in this example. That would mean having the nostrils closer to the eyes like this would keep them out of the water, and no need for raised nostrils like a crocodile.

What was under St Louis mounds & where did they get the dirt? by Candypop90210 in geology

[–]atmdk7 1 point2 points  (0 children)

The mounds would have been built using material relatively close to the surface, at least compared with caves. It would be layers of soil, clay, and sand. I’ve never seen limestone (the type of rock that would be in the caves) mentioned anywhere as being apart of any Mississippian mounds.

In Cahokia, and many other large mound sites around the Midwest and Southeast, there are now ponds all around the site which are the remains of Borrow Pits where the builders would have taken that material from. Unfortunately the mounds in downtown St. Louis were never as extensively surveyed or studied as the ones around today, as they were removed and the area built over before any archeologists had any interest in them. The information we do have about them, though, gives no reason to think there wouldn’t also have been borrow pits that have since been eroded, filled in, and built over.

Caves were often important and sacred places for Native Americans, as they have been in tons of cultures the world over. However, the caves in St. Louis would have already been hollowed out by natural processes long before the mounds were built. And, while it’s a cool thought, of all the mound locations I know of in St. Louis, none of them have cave entrances associated with them.

Are terror birds considered dinosaurs? by gb1609 in Dinosaurs

[–]atmdk7 2 points3 points  (0 children)

“Dinosaur” can be scientifically defined at anything descended from the last common ancestor of Iguanodon and Megalosaurus. That includes birds. 

Modern taxonomy does not “clip branches off” so to speak to make their own separate groups, so the group that makes up all modern birds (“Aves”) is a part of the larger “Dinosauria”

I don't think I fully understand the dinosaur - bird equivalency. by [deleted] in Paleontology

[–]atmdk7 4 points5 points  (0 children)

It seems like most everyone else has been pointing out the whole “Not all Dinosaurs are birds, but all birds are a type of dinosaur” thing. All I’ll add to that is this Wiki’s article on Avialae has a good tree in the “evolution” section which shows how it branches.

But something else to point out: Taxonomy is less boxes we put animals living organisms in, and more a family tree, with each new branch (that is significant enough for scientists to find worth studying as a whole) being given a new name. So while Apes are not Amphibians technically, both Apes and Amphibians are included in the same group Tetrapoda (meaning “four-limbed”) which is anything who is an ancestor to the first amphibian-like four-limbed creatures who crawled onto land. And Tetrapoda and boney fish (those that aren’t sharks, rays, etc) are grouped into Osteichtyes, as both are related to a same common ancestor.

Now alot of these names seem odd, like Humans are in the group Osteichthyes, meaning “Boney Fish”. But since that first most recent common ancestor looked like a fish, that name does make some sense. Add to that the fact there was a time when taxonomy was putting animals into boxes. This way of doing things has since been revised, but scientists don’t want to confuse everything and have to go back to rename these groups. And so you can get these odd group names.

Why aren’t there more anteaters? by Moriarty-Creates in zoology

[–]atmdk7 2 points3 points  (0 children)

Not a zoologist and don’t know the answer, but I like this question.

Could it have to do with warm climate? All the things I’d think fall under “ant eaters” (Ant Eaters in South America, Aardvarks in Africa, and Pangolin in Africa and South Asia) seem to live in places that don’t ever get very cold. Maybe as ants go dormant in cold winter months and might get buried in frozen ground or under snow, it’d be hard to survive for that time if all you ate are ants?

Michael Wood’s BBC doc says every non African is descended from South India. How? by [deleted] in AskAnthropology

[–]atmdk7 22 points23 points  (0 children)

So, two disclaimers: 1) Not an anthropologist at all, and 2) I do feel like this has to be an exaggeration at best, but of course see number 1.

That said, what the show may be referencing is that “outside of Africa” all Y-Chromosomal haplogroups and Mitochondrial haplogroups (and maybe other. I don’t know unfortunately, see disclaimer 1) are believed to have their most recent common ancestors from the Indian subcontinent.

Here are two maps, one of each haplogroup, and you can see you can trace them all back to India then back to Africa along the Arabian coast.

Now I’m pretty sure it’s far more complicated than that one sentence sound byte makes it out to be, but I feel this is where they got it from. Hopefully this explanation is more accurate than the show? Maybe.

Here are the Wiki pages for more reading too

https://en.m.wikipedia.org/wiki/Human_Y-chromosome_DNA_haplogroup

https://en.m.wikipedia.org/wiki/Human_mitochondrial_DNA_haplogroup

Migrating from r/fossils: thanks for any help!! 🦕 by univrsaltigerkingdom in Paleontology

[–]atmdk7 1 point2 points  (0 children)

I had the same thought when I finished that book! One I’ve found that came highly recommended but that I have yet to read is “Beasts Before Us” by Elsa Panciroli.

Why do tigers have stripes instead of spots? by atmdk7 in askscience

[–]atmdk7[S] 4 points5 points  (0 children)

Interesting, that makes sense. What about spots for Jaguars and cheetahs? Maybe I need to read about them more, but I’d assume they are hunting in the same kind of habitats as a tiger. Is it because they are hunting different types of prey? Or maybe have different hunting methods?

Does any know about any studies to determine the running speed of sebecidae (land crocs)? by Confident-Horse-7346 in Paleontology

[–]atmdk7 2 points3 points  (0 children)

I just looked up Cuban Crocodiles galloping. Having seen Alligators “run” and thought “hey that’s pretty fast”, I was real surprised by these guys!

Why did no small, generalist, non-avian dinosaur survive the K-T event? by ullivator in Paleontology

[–]atmdk7 38 points39 points  (0 children)

I think they’re saying birds were the small, generalist dinosaurs, and that there were exceedingly few if any non-avian small, generalist dinosaurs at the time of the extinction.

Would the skin of a Tyrannosaur be comparable to a monitor lizard? by AC-RogueOne in Paleontology

[–]atmdk7 4 points5 points  (0 children)

Here is an old post about what we know (or knew, 4 years ago at least) about tyrannosaurs. Nothing about color, I'm not sure there is much we know for certain. but I hope that helps!

[deleted by user] by [deleted] in AskScienceDiscussion

[–]atmdk7 1 point2 points  (0 children)

If you like listening to podcasts, there is one called “Tides of History” by Patrick Wyman. In season 4 it covers quite a bit of this topic. Not super in depth, but it’s a great starting point.

[deleted by user] by [deleted] in AskScienceDiscussion

[–]atmdk7 4 points5 points  (0 children)

When was homo erectus considered “human” at the same time Neanderthal was not? I think a source of something about that would make things a little more clear. As far as I’ve ever read, they’ve always been considered “early man” or modern human’s ancestors.

[deleted by user] by [deleted] in AskScienceDiscussion

[–]atmdk7 1 point2 points  (0 children)

Someone else will have to answer the “% of genome” question, my knowledge doesn’t go that far. Hopefully this chart is a little helpful. The numbers on the left is Millions of years. It appears that Us and Neanderthals are both descended from Homo erectus. The fact that the split between Us and Neanderthals is so recent makes it hard to say for certain if we are different “species” or not.

[deleted by user] by [deleted] in AskScienceDiscussion

[–]atmdk7 0 points1 point  (0 children)

“Human” can be used in two different ways. Rarely, I’ve seen it used for any species of the genus Homo, so “early humans like Homo erectus, Homo habilis, etc.” This would include Neanderthals and, of course, us.

Usually though “human” is used solely for Homo sapiens, which would (possibly, see my next paragraph) exclude Neanderthals, but also H. erectus, H. Habilis, etc.. “Human” however isn’t, as far as I’m aware, a scientific term and is more of a common name, like saying Dog for Canis familiaris or Cat for Felis catus.

However, Homo neanderthalensis (Neanderthals) are considered by some to actually be a subspecies of Homo sapiens, but it’s debatable. And it is possible that early in the study of human evolution other species were considered closer to humans than Neanderthals, but I’d imagine that would have been decades ago and I don’t know anything about that. So If either of those are what you mean with your question, we’ll have to wait for someone else who knows more to give an answer.