On the Rocks: Where the boys are

Mastodon

You likely remember the discovery of the Hyde Park mastodon. That was back in 1999. A local family, the Loziers, wanted to enlarge the pond that was in their backyard. When work was underway, they noticed what they thought was a log. They soon realized that it was a bone, a bone so large it couldn’t possibly be from a cow or horse. After several attempts to be taken seriously, a professor from Bard College finally confirmed its identification. It turned out to be a humerus. The equivalent of a human upper arm bone but belonging to a mastodon (Mummat americanum). After weeks of pumping the water from the pond, followed by an intense excavation with the help of hundreds of volunteers, an almost complete skeleton was retrieved. Eventually, it was mounted and is on display at the Paleontological Research Institute’s Museum of the Earth in Ithaca.

The animal was an adult male between 30 and 40 years in age weighing between 10 and 15 thousand pounds. It was speculated that he was walking on the pond’s thin ice when he fell through and drowned. 

But, is that it; is that the whole story? Maybe not. Recently, an article in a professional journal called Current Biology focused on another type of elephant — the mammoth. Researchers were studying the genetics of 98 Siberian mammoths (Mammothus primigenius). They were surprised to find that 69 of them were males. When they studied the literature, they found that this was the norm. Wherever large numbers of mammoths (and probably mastodons) were found, similarly large percentages of them were males.

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They reasoned that, at birth, there likely had been an even number of males and females. So, what had happened to all those males? Why had so many of them died and, more importantly, why had they been preserved in such disproportionate numbers? Here is where we come across one of the leading philosophies of geology: “the present is a key to the past.” When geologists (and paleontologists too) come across a quandary from the distant past, they look to the present for a solution. 

In this case, the biology or better the sociobiology of modern elephants may offer a solution to the problem. Modern day elephant herds consist of females and juveniles. They are led by experienced older females. When male elephants reach maturity, they are expelled from the herds. The male elephants either live solitary lives or are found in smaller male-only herds. The thought is that experienced female matriarchs can lead their herds away from dangers that they have, from life experiences, learned about. But males, especially solitary males during periods of musth (mating seasons), are more likely to behave in reckless manners, fighting with other males and even attacking inanimate objects. They are risk takers and that leads to what mammoth researchers labeled as “silly” deaths. Such males are more likely to fall through ice, or sink into bogs. We have read about one particularly disturbing example. One male mastodon was preserved in a standing position, stuck in the muck that typically accumulated at the bottom of ponds and shallow glacial lake deposits. The poor animal seems to have died a slow death. But the good news is for us — when such things happen, their corpses are likely to end up buried where they can be better preserved and, many thousands of years later, discovered by especially bright primates. Members of female herds seem to die less dramatic deaths in locations, like on open tundra, where they are not likely to be so well preserved as the males.

Contact the authors at randjtitus@prodigy.net. Join their facebook page, The Catskill Geologist. Read their blogs at thecatskillgeologist.com.