Ask a question, get a proper answer

[Supercommunist]

I am pretty ignorant on bats. Forgot that they were vulnerable to the cold. I guess the thought experiment does help illustrate while all the giant marine and flying reptiles got wiped out.

They probably didn't have many small basal lifeforms to fall back on so the vacuum was left wide open.

[Exalt]

Wouldn't the squmates mentioned also struggle with the cold?

EDIT: Christ, I hate auto-correct.

[mechafire]

Sept 6, 2024 3:20:05 GMT 5 Infinity Blade said:

Sept 4, 2024 6:56:33 GMT 5 mechafire said:

Why is it that marine mammals don’t seem to need pelvic/anal fins? Most fish retained their back bottom flippers and the many marine reptiles kept their back legs even when they their tails were the main tools for propulsion. Is it related to vertical undulation not really benefitting from them?

I'd imagine so. It's a bit hard to get it clear through my head, but if a tail is moving directly to the side to propel something, it would probably help to have paddles (or at least fins), stabilizing the animal's body laterally

Yeah, seals do use horizontal undulation, though I suppose they aren’t really as concerned with staying right-side-up as fish are.

[mechafire]

Some open-ended canid-related questions.

What are your guys’ thoughts on Canis rufus, red wolves? Is it a valid or useful taxon? Does another classification work better?

Do you know of any good descriptions or images of Protocyon postcranial? I think I’ve read something that compared it with African wild dogs, which, considering they were both grassland-dwelling dogs, is probably to be expected. Though I can’t seem to find much data on this.

[Infinity Blade]

Oct 16, 2024 6:26:04 GMT 5 mechafire said:

Some open-ended canid-related questions.

What are your guys’ thoughts on Canis rufus, red wolves? Is it a valid or helpful taxon? Does another classification work better?

Do you know of any good descriptions or images of Protocyon postcranial? I think I’ve read something that compared it with African wild dogs, which, considering they were both grassland-dwelling dogs, is probably to be expected. Though I can’t seem to find much data on this.

Unfortunately not an expert on canid taxonomy (which I've known for at least a decade know is a mess), but I'm just going to go with the conclusion of this review.

1. Available evidence suggests that the historical red wolves constituted a taxonomically valid species.

2. Extant red wolves are distinct from the extant gray wolves and coyotes.

3. Available evidence is compatible with the hypothesis that extant red wolves trace some of their ancestry to the historical red wolves.

4. Although additional genomic evidence from historical specimens could change this assessment, evidence available at present supports species status (Canis rufus) for the extant red wolf.

www.ncbi.nlm.nih.gov/books/NBK542544/


As for Protocyon, (somewhat) luckily for you we apparently have a complete skeleton of it. I can't access the full paper (in fact it seems to have originally been published in Portuguese). Its limb proportions are described as being similar to those of a culpeo, and its body length similar to that of a maned wolf.

A complete skeleton of Protocyon troglodytes is reported. Only cervical vertebrae and foot bones of this species, collected by Lund, were known up to now. The skull agrees with that of Protocyon scagliarum from Argentina. Morphology of postcranial bones does not differ from that of a domestic dog. Limb proportions are similar to those of Pseudalopex culpaeus, a generalized Caninae, and body length similar to that of Chrysocyon brachyurus. The specimen was collected at Toca da Boa Vista, Municipio Campo Formoso, BA (40 degrees 51'39"W; 10 degrees 09'36"S). The fossil fauna known from this region suggests that the habitat was a mosaic of forests and open Cerrado. The large canid preyed on medium sized grazers or browsers but not on the megafauna, rare in the area. The variation found in upper and lower premolars among this specimen and other remains from Lagoa Santa region suggests that Brazilian and Argentinean specimens may belong to the same species.

eurekamag.com/research/019/816/019816384.php?srsltid=AfmBOopBNo_p9Zhlcea5035weYFF8QXEr5PmCYjm3BEUtgv4wonzY_tO

[sharkboy101]

Been thinking about this for a bit but if Killer Whales were to coexist with Otodus Megalodon and Livyatan Spp, would they have been competitors or common prey items like the Lee Creek Physeteroids? Would Orcas have bigger pods than today if they coexisted with these formidable predators?