Tyrannosaurs used 'sixth sense' to hunt prey

[UM-Bot]

The giant two-legged carnivores of the Cretaceous had more than just big teeth and jaws in their arsenal.

http://www.unexplained-mysteries.com/news/305936/tyrannosaurs-used-sixth-sense-to-hunt-prey

[switchopens]

Nonsense. According to Ken Ham, they ate coconuts, that's why they have sharp teeth!

[Eldorado]

Am wondering if they also had "gut feeling".

[Kismit]

This sixth sense is kind of like the electroreception in sharks. 

That's  quite interesting from an evolutionary perspective. Since this seems to be a predatory ability I wonder if ( because I don't know) there is an equivalent prey receptor, for want of a better description.

[oldrover]

2 hours ago, Kismit said:

This sixth sense is kind of like the electroreception in sharks. 

That's  quite interesting from an evolutionary perspective. Since this seems to be a predatory ability I wonder if ( because I don't know) there is an equivalent prey receptor, for want of a better description.

There's the lateral line in fish. 

[Kismit]

I'm no scientist but I can see how this electrical thing works well in water. I think I'm going to have to read the article thoroughly to see what the transferring medium was for T-Rex

[Unusual Tournament]

8 hours ago, Kismit said:

I'm no scientist but I can see how this electrical thing works well in water. I think I'm going to have to read the article thoroughly to see what the transferring medium was for T-Rex

I think on sharks its a gel like substance that excretes from the skin... so maybe its the same for these reptiles. 

[oldrover]

9 hours ago, Kismit said:

I'm no scientist but I can see how this electrical thing works well in water. I think I'm going to have to read the article thoroughly to see what the transferring medium was for T-Rex

I think the main problem with this is that the article stub doesn't really say much. The link is better, but still doesn't give you the nuts and bolts of the study. Osteological evidence for facial nerve channels is a reasonable method for inferring facial structures. Last one I read dealt with the evidence for loose 'mammalian' type facial tissue and the point where you can first infer it in the fossil record of stem mammals. The study is almost certainly right in what it says about the presence of these sensory areas, but the interpretation will be a little wild in the popular press, who tend to take one fragment of the discussion and hype it. 

[Kismit]

Actually had a thought. What if the T-Rex used this to hunt in the water..?

[oldrover]

1 hour ago, Kismit said:

Actually had a thought. What if the T-Rex used this to hunt in the water..?

Don't forget other living therapods have this in their beaks. And I don't think T rex's anatomy speaks well of a semi aquatic predator.  

Spinosaurus (my least favourite dinosaur) on the other hand definitely.

[Carnoferox]

4 hours ago, Captain Risky said:

I think on sharks its a gel like substance that excretes from the skin... so maybe its the same for these reptiles. 

Sharks use sensory organs called the ampullae of Lorenzini to detect electrical currents. The sensory organs in crocodilians and tyrannosaurs are called integumentary sensory organs (ISOs), and are used to detect changes in pressure and temperature. 

Edited March 31, 2017 by Carnivorfox

[taniwha]

5 minutes ago, Carnivorfox said:

Sharks use sensory organs called the ampullae of Lorenzini to detect electrical currents. The sensory organs in crocodilians and tyrannosaurs are called integumentary sensory organs (ISOs), and are used to detect changes in pressure and temperature. 

I think pit vipers have similar?

[Carnoferox]

9 minutes ago, taniwha said:

I think pit vipers have similar?

Snakes have the Jacobson's organ, which is actually a chemoreceptor used for smell. 

[taniwha]

2 minutes ago, Carnivorfox said:

Snakes have the Jacobson's organ, which is actually a chemoreceptor used for smell. 

Maybe t rex had one?

[Carnoferox]

2 hours ago, Kismit said:

Actually had a thought. What if the T-Rex used this to hunt in the water..?

Tyrannosaurus morphology is definitely not suited for a semiaquatic lifestyle. Arms that reduced would not be good for swimming at all. Additionally, actual semiaquatic dinosaurs like Spinosaurus and penguins have dense bones with severely reduced pneumaticity, which Tyrannosaurus lacks.

[Carnoferox]

8 minutes ago, taniwha said:

Maybe t rex had one?

The ISOs of tyrannosaurs have different functions than a Jacobson's organ. ISOs are used to detect changes in pressure and temperature, whereas a Jacobson organ is used for smell. Although the Jacobson's organ is known from amphibians, lizards, and some mammals, no known archosaurs have them, so I highly doubt tyrannosaurs would have had one. Tyrannosaurs are also known to have had large olfactory bulbs, so they probably would have had a keen sense of smell anyway.

Edited March 31, 2017 by Carnivorfox

[taniwha]

2 hours ago, Kismit said:

Actually had a thought. What if the T-Rex used this to hunt in the water..?

I would say the rain and mist yes.

[Carnoferox]

Here's a link to the actual study if anyone's interested (it's open access): http://www.nature.com/articles/srep44942

There's more than just the facial integument here. A new species of the tyrannosaur Daspletosaurus (D. horneri) is named. Evidence for anagenesis from D. torosus to D. horneri is provided. There's also info on the ontogeny and biogeography of tyrannosaurs. It's a fascinating paper.

[taniwha]

5 minutes ago, Carnivorfox said:

The ISOs of tyrannosaurs have different functions than a Jacobson's organ. ISOs are used to detect changes in pressure and temperature, whereas a Jacobson organ is used for smell. Although the Jacobson's organ is known from amphibians, lizards, and some mammals, no known archosaurs have them, so I highly doubt tyrannosaurs would have had one.

Interesting. Do you suppose then the t rex was a nocturnal hunter or just had poor eyesight or colour vision?

[Carnoferox]

Just now, taniwha said:

Interesting. Do you suppose then the t rex was a nocturnal hunter or just had poor eyesight or colour vision?

To the contrary, Tyrannosaurus had large optic lobes and binocular vision, meaning that its eyesight was just as great as its sense of smell. The whole "poor eyesight" thing is yet another myth from Jurassic Park.

[Carnoferox]

1 hour ago, oldrover said:

Don't forget other living therapods have this in their beaks. And I don't think T rex's anatomy speaks well of a semi aquatic predator.  

Spinosaurus (my least favourite dinosaur) on the other hand definitely.

Spinosaurus is actually my favorite dinosaur. There is evidence that Spinosaurus may also have had ISOs on its snout: http://science.sciencemag.org/content/early/2014/09/10/science.1258750.full

Quote

A concentrated array of neurovascular foramina open on the anterior end of the snout and appear similar to foramina in crocodilians that house pressure receptors that detect water movement. 

 

[taniwha]

10 minutes ago, Carnivorfox said:

To the contrary, Tyrannosaurus had large optic lobes and binocular vision, meaning that its eyesight was just as great as its sense of smell. The whole "poor eyesight" thing is yet another myth from Jurassic Park.

Well if it was used to detect changes in pressure and temperature, is it less of a prey radar and more of weather radar?

I suppose it would be a sensory aid for delicate tasks such as nuzzling eggs or tracking animal droppings and footprints?

And combining the I SO with the binocular eyes do you think it's possible it had thermal vision?

Edited March 31, 2017 by taniwha
Furthermore

[Carnoferox]

7 minutes ago, taniwha said:

Well if it was used to detect changes in pressure and temperature, is it less of a prey radar and more of weather radar?

I suppose it would be a sensory aid for delicate tasks such as nuzzling eggs or tracking animal droppings and footprints?

The authors of the study speculate that there would have been multiple possible uses for tyrannosaur ISOs, but probably not for tracking prey. The UM article seems to be confused about the actual function of ISOs in tyrannosaurs (either that or it's using the misleading title to garner attention).

Quote

If our soft–tissue inferences regarding the presence of flat facial scales and ISOs are correct, then behavioral inferences for tyrannosaurids can be drawn based on comparison with crocodylians. Tyrannosaurids had a highly sensitive facial tactile system that functioned in prey capture, and object identification and manipulation, given the skeletal similarities with crocodylians. In crocodylians the bony casements around the nerve branches protect them from injuries sustained during communal feeding while maintaining highly sensitive skin; given the similarity in foramen morphology, this protective function was present in tyrannosaurids (whose bony oral margins often show lesions), showing that this multipurpose cephalic tactile system was not limited to life in an aquatic environment.

Assuming that crocodylians are suitable models for dinosaur behavior, and that tyrannosaurids were primarily terrestrial, tactile stimulation, such as rubbing, was probably more important in tyrannosaurid agonistic behavior than detecting water borne vibrations. As in crocodylians, female tyrannosaurids would have relied upon ISOs on the snout for detecting the optimal temperature of a nest site, and for maintaining nest temperature and the nest materials; also, ISOs would have aided adult tyrannosaurids in harmlessly picking up eggs and nestlings and, in courtship, tyrannosaurids might have rubbed their sensitive faces together as a vital part of pre-copulatory play.

 

Edited March 31, 2017 by Carnivorfox

[paperdyer]

Without an eyeball to study the rods and cones on the T-Rex we'll have to reply on present day lizards for the color vision answer.  Since the T-Rex used this new feature, I'd suspect it's color vision wasn't too well developed.

[Carnoferox]

4 minutes ago, paperdyer said:

Without an eyeball to study the rods and cones on the T-Rex we'll have to reply on present day lizards for the color vision answer.  Since the T-Rex used this new feature, I'd suspect it's color vision wasn't too well developed.

Lizards are not at all a good comparison for tyrannosaurs, since they are not closely related. Better comparisons would be modern archosaurs like crocodilians and birds, which do indeed have well-developed color vision. 

Edited March 31, 2017 by Carnivorfox