The Lurkdragon's Lair

Fifty percent animals, fifty percent fandom, one-hundred percent nerd.

Posts tagged predation

423 notes

allosauropteryx:

dinosaurquillstudio:

miss-beasty:

dinosaurquillstudio:

I’ve always wondered why paleo artists always give theropods a crocodilian mouth, where you can see the corner of the mouth muscles. 

If you look at a crocodilian skull the back of the upper jaw moves away from bottom jaw and Pterygoid(the bone in the back of the throat) is exposed and extremely pronounced. This would show that there is a major muscle there to connect the jaws together.

Where as with birds the upper jaw comes towards the bottom jaw, thus the corner of the mouth becomes a lip, and tends to meet under the eyes. 

This is about the same for theropod dinosaurs. They always have the fenetre laterotemporale(the large hole behind the head) where a lot of the jaw muscles attach and feed behind the jugal bone and to the bottom jaw. I would expect more of a bird mouth with lips rather than a muscular pink tissue that would be showing off and more of a hidden muscle like a bird mouth.

now I could be wrong, but after working as a bird taxidermist and seeing how bird mouths work and look and after working on an alligator, i can see a major difference between the two. 

Theropod dinosaurs don’t have the massive gap between the jaws that would possibly suggest more of a reptilian/crocodilian mouth, and would seem to have more of the bird like lip. Especially considering that theropod dinosaurs are the ancestors of birds, I would expect more of this.

I’ve never been to a dinosaur museum and the ones here are only replicas(allosaurus, triceratops, and apatorsaurus) so i’m limited at what skulls i can look at in person to better exam them, and the internet is so limited as to what angles I can see these skulls and if they are replicas/sculptures, or the real deal….and I can’t rotate them to get a full 360 view of what they look like….so this is the best that I can do with the resources I have.

I did a quick sketch of a Dilophosaurus skull and a fleshed out head at the top, the rest are google images i used as examples to better explain this.

Wow, I have never observed this difference before! It looks spot on to me, very astute. It makes sense that with all their birdy traits, they’d have birdy facial structure. Lovely sketch too (:

Thank you :D

And to further add onto this, if you look at these photos below, it further shows how the muscles attach in the skull of theropods, birds, and crocodilians, to further add onto this.

Theropod muscle attachments.

Bird Muscle Attachments

and crocodilian muscle attachments

now you have a more x-ray view of the differences.

The muscles attach in a completely different way and considering crocodilians have grown on a seperate branch of evolution that of dinosaurs and birds(even though they have the gene to grow feathers). 

I wonder though if scientists have thought of this idea….I can understand with bigger theropods like tyrannosaurus or spinosaurus with having a bit of the pink muscle showing, but some bird species also somewhat show off a bit of meat in the corner of the mouth when they open them….but there would still be a closed lip gap under the eye to some extent, and not a crocodilian smile we see most of the time in paleolithic art.

as seen here….the gap would be a closed solid piece of skin.

I guess this would fall under the book “All Yesterdays” idea of a “shrunken skeleton”.

First, that bird skull isn’t from a bald eagle, it’s from a barn owl (same picture is, in fact, here on Wikipedia). I’m not sure what’s going on in the live-eagle picture, but that’s either a bad photoshop, a deformed beak, or a poor prosthetic. Actual, normal bald eagle skull and head:

Speaking as a very amateur paleontographer, I’d say it’s probably mostly one of the “artmemes” for this generation or so. Everyone “knows” that’s what dinosaurs look like because they’ve been seeing that general reconstruction since childhood in all kinds of models and artwork.

If you’re looking at birds, most raptors and passerines actually aren’t the best as the tissue that lines the corner of their mouth is essentially still beak, though it’s softer. Parrots, despite having a number of naked-faced species, are also highly modified and have, as I understand it, some unique mouth muscles.

The birds I’d recommend for dinosaurmouths are California Condors (naked skin shows underlying structures better, and they have a cheek-like extension of skin to give a more accurate cheek option for herbivores), gulls of all kinds (no gape, and are always making rude faces and trying to eat things bigger than their heads), ostriches (less derived, simple feathers on head), and galloanserans including chickens and geese (less derived, common, and have common behaviors that include a wide open beak)

bonus: never seen anyone add teeth to a tyrannosaur’s tongue, do it and see how it goes. Everyone gives dinosaurs boring crocodile tongues anyway.

I would like to add that, particularly for primitive theropods and sauropodomorphs, you should probably take a look at some non-archosaurian reptiles. Dinosaurs were not lepidosaurs or turtles, yes, but turtle beaks can give some better idea what to do with your ornithischians, and lepidosaurs are relatively conservative.

All pictures are from Wikimedia Commons (01, 2, 3, 4, 5, 6) , except the Haliaeetus skull, which is from Digimorph. Digimorph is a great source of skull images for many species, including several fossil dinosaurs and some birds, and most specimens have very useful rotating views.

(via prehistoric-birds)

Filed under long posts predation dinosaurs reference birds queue

1,379 notes

rhamphotheca:

Major discovery: Wolves help trees grow, rivers flow, countless species flourish
by Michael Graham Richard
It might not seem obvious at first, but wolves can have a huge indirect effect on ecosystems. They aren’t just good for reducing deer populations and such; they fundamentally change how these herbivores behave, where they graze and which areas they avoid.
This means that trees and plants start growing again in places that were overgrazed, giving shelter to all kinds of species (songbirds, beavers, rabbits). This in turns changes how the local ecosystem works further, providing more ecological niches to more species, until after a few years the area is almost unrecognizably more alive! All this thanks to wolves, this underrated apex predator!
Check out the great video below to see the chain of events in action after wolves were reintroduced in Yellowstone after an absence of about 70 years…
(find out more: TreeHugger)

rhamphotheca:

Major discovery: Wolves help trees grow, rivers flow, countless species flourish

by Michael Graham Richard

It might not seem obvious at first, but wolves can have a huge indirect effect on ecosystems. They aren’t just good for reducing deer populations and such; they fundamentally change how these herbivores behave, where they graze and which areas they avoid.

This means that trees and plants start growing again in places that were overgrazed, giving shelter to all kinds of species (songbirds, beavers, rabbits). This in turns changes how the local ecosystem works further, providing more ecological niches to more species, until after a few years the area is almost unrecognizably more alive! All this thanks to wolves, this underrated apex predator!

Check out the great video below to see the chain of events in action after wolves were reintroduced in Yellowstone after an absence of about 70 years…

(find out more: TreeHugger)

Filed under wolves canines yellowstone queue predation

269 notes

apsaravis:

aspacelobster:

prehistoric-birds:

prehistoric-birds:

I want a talking-but-otherwise-reasonably-realistic animal story about the ancestors of today’s birds struggling to survive the nuclear winter brought on by the K-Pg impact. There’s plenty of potential for drama considering the inevitable competition for warm places to sleep and the right to eat what few photosynthetic organisms have managed to survive the lack of sunlight.

Adding on to this:

"Omnivores, insectivores and carrion-eaters survived the extinction event, perhaps because of the increased availability of their food sources. At the end of the Cretaceous there seems to have been no purely herbivorous or carnivorous mammals." (source)

So these birds could eat meat. Imagine them banding together out of sheer desperation where food is the scarcest and going cannibal. They can’t dwell on the horror of their situation for too long or else they’ll completely lose it. Besides, what choice do they have, right? At least, that’s what they have to tell themselves, over and over and over and…  

There could also be a group of birds who are essentially Social Darwinists, thriving even in these deadly times by supplementing their food supply with the weak of their own kind. If you strike them as a survivor there just might be a place for you in their ranks. Refuse and you join them anyway—from the inside of some bird’s gut.

can the opening sequence be of a mammal crawling around inside something, then it climbs out onto what becomes clear as a dinosaur skull as the camera zooms out.
the mammal lifts it’s forepaws of the ground and sniffs the air as uplifting music plays.
then BAM the mammal gets nailed by a bird.

-IMPACT WINTER-

Here you go:

image

image

To be continued…

(via prehistoric-birds)

Filed under impact winter long posts animal death predation dinosaurs prehistoric life queue

845 notes

sciencesoup:

Wave Wash

When summer descends on the Antarctic, the sea ice breaks into chunks called pack ice. Seals often haul themselves up onto them, but they’re not a safe place to rest—not if a pack of killer whales finds you.

Killer whales are top predators with complex social relationships, so they hunt in groups, and they hunt well. In 2009, Dr Robert Pitman and Dr John Durban, marine scientists at NOAA, studied the whales’ extraordinary hunting tactic called “wave-washing” with a crew filming the documentary Frozen Planet, off the western Antarctic Peninsula.

Here’s how it went down: The whales line up, sometimes seven abreast, and charge towards the ice floe where the poor seal is stranded. Then, as they dive under it, they work together to kick up their tails and create a wave that rushes over the ice. The whales repeats this an average of four times before the terrified seal is eventually knocked off, then they work to corner it, blowing bubbles and creating turbulence to create confusion, before finally drowning it.

The researchers also found that the killer whales actually skin and dissect their prey underwater before dividing it up between the group.

Previous research has shown that there are at least four distinctive types of killer whale living in the Antarctic, all with different colourings and behaviours, and this particular population is referred to as “pack ice killer whales.” These different groups don’t seem to mix even though their territories overlap, so more research needs to be done to see if they’re separate species of just different subspecies.

(Gif Credit)

(via fightingforwhales)

Filed under gif predation marine life wildlife polar life pinnipeds cetaceans orcas dolphins queue long posts

158 notes

paramortality asked: I was watching QI, and there was a question on a vegetarian spider. Do you know anything about it?

bogleech:

Yep, Bagheera kiplingi, named in honor of the Jungle Book, feeds on tiny nutrient capsules produced by a species of Acacia tree.

These trees live in close symbiosis with ants, producing the capsules entirely to feed the ants who live in its hollow outgrowths and defend it from pests.

The spider carefully sneaks around the tree, dodging ants with its sheer agility and gets most of its food from plant matter, but it’s not completely vegan; it will also sometimes steal the eggs, larvae and pupa carried by ant workers!

Filed under predation bagheera kiplingi spiders wildlife neato

1 note

Condor Watch

Hey, wanna help scientists study the endangered California Condor? Here’s your chance!

With Condor Watch, you’ll be helping researchers ID condors to help them figure out what, if anything, their social structure has to do with who gets lead poisoning from animals killed by lead bullets. You’re presented with photos from feeding stations and asked to ID what scavengers are there, and if condors are present, things like their ID tags and age.

There are a lot of mangled animal carcasses at the feeding stations which some viewers may find upsetting, so careful there if gore and/or animal death is something you’re sensitive to. Zooniverse has plenty of research projects you can help out with, but as a Pacific Northwest native the California Condors are really important to me, so I though I’d get the word out.

Filed under condors california condors wildlife birds conservation predation scavenging zooniverse