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avatar_CarnegieCollector

Things dinosaurs may have had or did

Started by CarnegieCollector, August 16, 2016, 06:43:12 PM

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stargatedalek

Also worth noting the closest analogues, birds, only rarely form true packs. Only corvids and Harris's hawks will truly hunt as a cohesive pack in the same sense as wolves, although many diving birds and birds of prey will hunt cooperatively.


Papi-Anon

Let's also take into account that having a social-structure at the level of being a pack requires a certain amount of neurological development and evolution. Maniraptorans had some of the most well-developed brains of their time (though most modern birds are comparatively more intelligent and complex in their brains' designs). Pack-hunting at the level of modern mammals such as wolves or orcas is really not the norm throughout Chordata with social-bonds. Given non-avian members of the maniraptorans were arguably the most intelligent extinct dinosaurs I don't doubt life-long mating at all, but a structured pack like a lion pride or wolf pack seems (to me) like wishful thinking for creatures that with brains less developed than modern birds. Hell, I kinda doubt most Eocene predators did anything beyond a life-pair once the kids were big enough to fend for themselves.

As for my wonderings on dinos:

-Intricate mating rituals (I read about some evidence of males competing by scratching the ground in a mock nest-making display based on scratch-marks that were preserved).
-Regurgitated food for young vs. un-processed bitten-off chunks.
-Albinism (I'm sure it happened once in a while, it's fun to think of a ghostly-white Rex with red eyes).
-Cases of gigantism/dwarism in individuals that were not the norm.
-How often herds protected one another as opposed to just fleeing in an 'every dino for themself!' mentality to rejoin later.
-Hypertrophy of features not usually seen in a genus.
-Pathological conditions that may not have necessarily impaired the ability to survive but still were abnormal. Like mange in mammals, or having an limb with asymmetrical features.
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Quote from: stargatedalek on August 30, 2016, 10:39:08 PMAlso worth noting the closest analogues, birds, only rarely form true packs. Only corvids and Harris's hawks will truly hunt as a cohesive pack in the same sense as wolves,

1stly, I assume by "a cohesive pack", you mean a true cooperative group of 3 or more. If so, then "corvids and Harris's hawks" aren't the only ones (E.g. See the Tudge quote).

2ndly, based on what I've read, "a pack can be as small as a pair" ( http://www.painteddog.org/the-dogs/pack-life/ ). I mentioned this in my previous post on page 2. Point being, pack hunting "may be important for many raptors" (in reference to Ellis et al. 1993).

3rdly, for those unfamiliar w/the various classes of social foraging, Ellis et al. 1993 neatly sorts them out ( http://www.jstor.org/discover/10.2307/1312102?uid=3739952&uid=2&uid=4&uid=3739256&sid=21102524819193 ). If you can't get past the paywall, the 1st 2 pages of Orellana & Rojas 2005 sums them up ( https://www.academia.edu/3513923/Possible_social_foraging_behavior_in_the_Red-backed_Hawk_Buteo_polyosoma_ ). There's non-cooperative hunting, cooperative searching, pseudo-cooperative hunting, & true cooperative hunting (I.e. Pack hunting as defined by field biologists who have studied social foraging in a wide range of animals).

Quoting Tudge (See The Bird: A Natural History of Who Birds Are, Where They Came From, and How They Live):
QuoteThe sociality that is encouraged by the diet tends to spill over into all aspects of life. So it is that hornbills are fruit eaters and also, as we will see in Chapter 7, are outstandingly social breeders, with various kinds of social arrangements. But also among hornbills we see an interesting twist—where the innate sociality has in turn become adapted to a quite different kind of feeding. For among the biggest of all hornbills, and in various ways distinct from the rest, are the two species of ground-hornbills from Africa. Ground-hornbills are not mere fruit eaters: they are formidable predators. The beak is like an icepick. They can hack their way into a tortoise. The Northern species is among the biggest of all avian predators. The ancestors of ground-hornbills were presumably fruit eaters, and that, perhaps, is how they first evolved their sociality. Now, as predators, they hunt in packs. Typically they chase some hapless creature like a hare into a bush and then some act as beaters while others lie in wait and deliver the coup de grace. The packs are usually family groups. They can be seen as strategic predators like wolves or perhaps as problem families, terrorizing the neighborhood.
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HD-man

#44
Quote from: Crash on August 31, 2016, 05:18:35 AMLet's also take into account that having a social-structure at the level of being a pack requires a certain amount of neurological development and evolution. Maniraptorans had some of the most well-developed brains of their time (though most modern birds are comparatively more intelligent and complex in their brains' designs). Pack-hunting at the level of modern mammals such as wolves or orcas is really not the norm throughout Chordata with social-bonds. Given non-avian members of the maniraptorans were arguably the most intelligent extinct dinosaurs I don't doubt life-long mating at all, but a structured pack like a lion pride or wolf pack seems (to me) like wishful thinking for creatures that with brains less developed than modern birds. Hell, I kinda doubt most Eocene predators did anything beyond a life-pair once the kids were big enough to fend for themselves.

Actually, based on what I've read (E.g. See the following quotes), non-bird maniraptorans 1) were similarly intelligent to chickens, & 2) had the intelligence for pack hunting. Furthermore, chickens 1) "probably fall about mid-range on the intelligence scale of birds" ( https://books.google.com/books?id=Ct4-qGkuC-kC&pg=PA34&dq=%22fall+about+mid-+range%22&hl=en&sa=X&ved=0ahUKEwjw-cjpgOvOAhXKJx4KHS2lCx4Q6AEIKjAC#v=onepage&q=%22fall%20about%20mid-%20range%22&f=false ), & 2) "have cognitive capacities that are beyond those of both dogs and cats" ( http://www.huffingtonpost.com/bruce-friedrich/if-you-wouldnt-eat-a-dog-_b_698286.html ).

Quoting Walsh (See page 270: http://www.academia.edu/1061233/Directions_in_Palaeoneurology ):
QuoteIt is now clear that while some theropod clades pos-sessed typically 'reptile'-like brains (Giffin et al. 1988; Gif-fin 1989; Rogers 1999; Brochu 2000; Franzosa and Rowe 2005; Sanders and Smith 2005; Witmer and Ridgely 2009), at least some maniraptoran theropods had surpris-ingly bird-like brains (Kundra´t 2007; Balanoff  et al. 2009; Norell et al. 2009). In these taxa, not only is the telen-cephalon significantly enlarged (sometimes to an extent greater than in Archaeopteryx), but flight-related regions such as the cerebellar flocculus, which are especially enlarged in birds, are also very well developed (Kundra´t 2007). This has fuelled the debate about whether these taxa, which often bear feathers, are in fact secondarily flightless birds rather than bird-like theropods (Witmer 2009; Kavanau 2010).

Quoting Burish et al. (See the 1st page: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.583.8968&rep=rep1&type=pdf ):
QuoteVertebrate brains vary tremendously in size, but differ- ences in form are more subtle. To bring out functional contrasts that are independent of absolute size, we have normalized brain component sizes to whole brain vol- ume. The set of such volume fractions is the cerebrotype of a species. Using this approach in mammals we pre- viously identified specific associations between cerebro- type and behavioral specializations. Among primates, cerebrotypes are linked principally to enlargement of the cerebral cortex and are associated with increases in the complexity of social structure. Here we extend this analy- sis to include a second major vertebrate group, the birds. In birds the telencephalic volume fraction is strongly cor- related with social complexity. This correlation accounts for almost half of the observed variation in telencephalic size, more than any other behavioral specialization ex- amined, including the ability to learn song. A prominent exception to this pattern is owls, which are not social but still have very large forebrains. Interpolating the overall correlation for Archaeopteryx, an ancient bird, suggests that its social complexity was likely to have been on a par with modern domesticated chickens. Telencephalic vol- ume fraction outperforms residuals-based measures of brain size at separating birds by social structure. Telen- cephalic volume fraction may be an anatomical sub- strate for social complexity, and perhaps cognitive abili- ty, that can be generalized across a range of vertebrate brains, including dinosaurs.

Quoting Buchholtz (See Brett-Surman et al.'s The Complete Dinosaur, Second Edition):
QuoteEndocasts of small coelurosaurs (Russell 1969, 1972; Colbert and Russell 1969; Kundrát 2007) display a strikingly different anatomical pattern (Fig. 10.6). They retain details of brain anatomy and roofing bone sutures on their surfaces, suggesting that the brain filled the braincase nearly completely. Brain flexures are minimal and olfactory bulbs are small, indicating that smell was not a dominant sense. Cerebral hemispheres are separable, convex, and expanded laterally and/or posteriorly (Kundrát 2007), suggesting an active intelligence. The large optic lobes are visible either dorsally or displaced laterally by the large cerebrum, as in living birds. Russell (1969) associated the large optic lobes with large eyes and binocular vision, and it is likely that sight was the dominant sense. Kundrát (2007) described an expanded cerebellum with presumptive cerebellar folia among the avianlike characters of the oviraptorid theropod Conchoraptor, inferring excellent balance and coordination.
Encephalization quotients of small coelurosaurs vary with predictions of body mass and percentage of braincase fill, but even conservatively, they are far higher than those of any other dinosaur group, overlapping those of living birds (Hopson 1977; Kundrát 2007). Larsson et al. (2000) estimated cerebral volumes by superimposing ellipsoids on endocasts with surficial indications of cerebral extent. Their data suggest at least three stages of increase of relative cerebral size to total brain size over a period of only 40 million years: of coelurosaurs over allosaurs, of Archaeopteryx over coelurosaurs, and of ornithurine birds over Archaeopteryx. The high encephalization values of small coelurosaurs indicate an active, complex, and social lifestyle that agrees well with their frequent interpretation as pack hunters.
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CarnegieCollector

Ok, im all over the albino dinosaurs. Pretty much any albino thing is awesome looking. There is another variation of skin pigmentation that is the opposite of albinism, that makes the creature all black, I just can't remember what that's called  :P

Just so I'm on the same page as everyone else, by "inflatable sacks", we are talking about the sacks that things like toads, frogs, and frigate birds have on their necks, right?
Is there an alternate universe in which dinosaurs collect figures of people?

Halichoeres

Quote from: CarnegieCollector on September 07, 2016, 04:15:25 AM
Ok, im all over the albino dinosaurs. Pretty much any albino thing is awesome looking. There is another variation of skin pigmentation that is the opposite of albinism, that makes the creature all black, I just can't remember what that's called  :P

Just so I'm on the same page as everyone else, by "inflatable sacks", we are talking about the sacks that things like toads, frogs, and frigate birds have on their necks, right?

Melanism :)

There is also a phenomenon similar to albinism, called leucism. It can be the result of defects in pigments other than melanin, and doesn't cause the famous pink eye effect.
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I know everyone wants to see hunting behaviour but you know I want to see?

MATING DISPLAYS.

I know there's the obvious ones with crests and stuff, but imagine all the ones that didn't fossilise. Crazy bright colours and complex dances among the most unlikely animals.

And parenting behaviours! Single T. rex dads wandering around with gaggles of baby tyrants underfoot!
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Quote from: Brontozaurus on September 29, 2016, 10:25:17 AM
I know everyone wants to see hunting behaviour but you know I want to see?

MATING DISPLAYS.

I know there's the obvious ones with crests and stuff, but imagine all the ones that didn't fossilise. Crazy bright colours and complex dances among the most unlikely animals.

And parenting behaviours! Single T. rex dads wandering around with gaggles of baby tyrants underfoot!
Same here. Modern dinosaurs have a lot of special and unique abilities just to attract mates, so I strongly believe that extinct dinosaurs were no different.

CarnegieCollector

Quote from: FlaffyRaptors on September 29, 2016, 10:44:32 AM
Quote from: Brontozaurus on September 29, 2016, 10:25:17 AM
I know everyone wants to see hunting behaviour but you know I want to see?

MATING DISPLAYS.

I know there's the obvious ones with crests and stuff, but imagine all the ones that didn't fossilise. Crazy bright colours and complex dances among the most unlikely animals.

And parenting behaviours! Single T. rex dads wandering around with gaggles of baby tyrants underfoot!
Same here. Modern dinosaurs have a lot of special and unique abilities just to attract mates, so I strongly believe that extinct dinosaurs were no different.
Maybe, to attract mates, male tyrannosaurs wore fancy tuxes and took she-rexes on dinner dates to Olive Garden?
Is there an alternate universe in which dinosaurs collect figures of people?