Crestfallen
Posted by Graeme Lyons , Thursday 23 February 2012 18:54
And to rule out dog, which have very different hind molars, here are the only teeth present.
So this has been a pet hate of mine for years. And after a rant on Twitter recently, I thought it was best to put all my thoughts down on th...
More and more people feed badgers these days. Maybe this individual got regular servings of dog food or similar?
With regards to differences in crests/bony processes: I was at the Jorvik centre in York recently and they have a few skeletons on display there. One of them was presumably a young warrior with several nasty nicks on his bones. You could really see the much larger processes on his arms where his biceps attached, especially compared to the remains of the townsfolk also on display. I think they identify archers at battlefield digs in a similar manner.
Cubs start off without the interparietal ridge/sagittal crest, don't they? I have found full size skulls with no ridge before and assumed they were badgers who died, probably in their first winter. However with all the fierce play biting they do through their first summer (and beyond) you might think the ridge would develop more rapidly.
Hi Graeme, Interesting. The age explanation is also given in an old edition of 'Mammals of Britain - their tracks trails and signs' by Lawrence and Brown which says 'the sagittal crest is well developed, especially in old mature animals'. Maybe it isn't a diet difference then - just that your second skull is of a young adult that hasn't had the time to develop the crest yet?
However, they do seem remarkably different...
Allan
I found a very similar full sized badger skull recently and it also perplexed me! No crest, and further the lower jaw was detached like yours, which is usually impossible to do so without breaking the jaw. I had wondered if this missing jaw may have been a result of badger baiting... but now I reckon the jaw and crest oddities must be connected, resulting in an unusually weak bite. The 'soft food' only hypothesis is very interesting! I had also wondered if this may have been the result of genetic mutation or inbreeding, a weak jawed runt! I showed my father, also an ecologist, and at first he refused to believe it was a badger due to the missing crest and jaw, but I found it from a definate badger carcass! Plus I've just checked the molars, thanks to your ID tip there. Cheers for this! What a coinkidink!
Continued thoughts on this! - It doesn't make sense that the crest would be missing simply due to a soft food diet: muscle mass will build up with use, but the bone growth that the muscle attaches to cannot! Bone growth is determined genetically, it's either there or it isn't. It can't develop from a need to connect increased muscle mass! Also it has been shown that cubs lack the crest, so therefore the genes that allow/cause this growth are 'turned on' and expressed in adulthood due to a factor relating to time or some seasonal trigger. Therefore i beleive it is more likely this lack of crest, on these large adult skulls, along with reduced jaw size (allowing it's removal), is down to those genes not being triggered, or are themselves defective copies etc. A plausible cause of this may be due to increased isolation of populations, and therefore inbreeding. I'd be very interested to hear any further thoughts on this!! Cheers! Charlie
Hi Charlie
Although I believe you could well be right about the genetic character traits, bone DOES change with increased use of the associated attached muscles. The shape of bones of human remians for example, is often used to show how muscular the owners were likely to have been. I do not believe it is likely to be the only part of this mystery, but we can't totally rule it out. Thanks for your comments by the way.
Graeme
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Sounds about right fella - bone does grow/mould itself inline with muscle development - I have seem similar ridge structures on other mammals and showing a variety
of ridge sizes within same species - so cranial crest would mirror muscle dev as a result of feeding behaviour/environment/food availability - gud call :)