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Hamipterus

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A couple of overly dramatic Hamipterus tianshanensis, a newly described pterosaur from the Early Cretaceous of what is now China.

At least 40 individuals of Hamipterus, and a few eggs, were found, which instantly makes it one of the best known pterosaurs. Among them, there are bigger individuals with big, showy head crest, and smaller ones with smaller crests. The researchers suggest the big ones are males and the small ones females. This would suggest a promiscuous mating system with intense competition between males, perhaps lekking or harems.

It can't be, at least yet, ruled out that the animals are simply of different ages. Or, the big ones might actually be females, if the species has a reversed mating system or some other aspect of their biology favoured big females (or small males). It's not as common as the other way around, but in no way unheard of either.

In any case, an awesome discovery.

The description paper is open access, and can be found here: www.cell.com/current-biology/a…

Dave Hone also wrote a nice article about Hamipterus on The Guardian: www.theguardian.com/science/lo…
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Jdailey1991's avatar
After watching one episode of BBC's "The Life of Birds", I believe you.
TrilobiteCannibal's avatar
I love this picture, the colors and the crest just look awesome.
Terizinosaurus's avatar
VERY NICE JOB!!!:) (Smile) 
Valeriolete's avatar
They are beautiful.
Since when are females being the dominate gender rare? If anything they are the norm.
Even in species with sexual dimorphism, the females get to make the choices, not the males.

So, in almost all species, females are larger and more dominant (sharks, most fish, baleen whales, falcons, owls, snakes, etc) or females are smaller yet more dominant as they make the decisions (anything where males are larger or have display features)
Eurwentala's avatar
Do note that I never used the word "dominate". I don't think it's an useful way to think about relationships between genders in most cases anyway. There's a lot going on, and it's not often one sex has some overall advantage over the other.

My wording was "reversed mating system", which is a scientific term simply referring to systems where the male has a larger allocation of resources to breeding. Thus, males tend to be more choosy, while females in these species are more showy and actively compete for the attention of males. These are comparatively rare compared to the two other mating systems your comment describes, though not unheard of. Seahorses and pipefishes, jacanas and pharalopes are examples.
I think though in many species females have more resources and use them more.
Eurwentala's avatar
Perhaps, though that wasn't really my point either. It's which gender allocates more to breeding and thus limits the number of offspring, specifically, that has a lot of interesting consequences in behaviour and sexual dimorphism. It's usually the female, though. Even without any parental care, the female has (by definition) to produce larger, costier gametes.
True.

But maybe it is exactly because of this that the females have the options, because they can't afford to waste their costlier reproductive cells.
Eurwentala's avatar
Yeah, I think that's pretty much it.
Helixdude's avatar
Females being larger might actually make sense. Larger organisms process energy more efficiently and can produce more eggs. This occurs many species of amphibians and dinosaurs such as Tyrannosaurs have been documented having females as the larger sex
Eurwentala's avatar
Yes, in many species females are larger than males. But no such thing has been documented from tyrannosaurs. The largest known fossil Tyrannosaurus is called Sue, but it's only a name: there's no way to know Sue's gender.
Helixdude's avatar
Thanks for correcting me on the Tyrannosaurs, but it's still a viable concept.
Eurwentala's avatar
Yeah, sure is. :) It just depends on the mating system. Polygamous or monogamous, territoriality or not, k or r selectivity.
AngelCnderDream14's avatar
Awe that is so cute!
Kaijukid23's avatar
I thought it has 2 heads
olofmoleman's avatar
I love this one.
WillemSvdMerwe's avatar
Ooh, great illustration!  Pterosaurs rool!
Found you via io9. Love your work!
Eurwentala's avatar
Thanks!
I just found out about the io9 feature myself, when I started to wonder about the sudden flood of visitors. I'm quite excited. :)
Traheripteryx's avatar
Awww such a cute pair! :meow:
sketcherjak's avatar
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