With many fossils, particularly vertebrates, small fragments can sometimes be very informative and justify close scrutiny. That was the case with a pair of associated bones from Diamond Valley Lake. One of the fragments, shown above, includes the occipital condyles that form the articulation between the skull and the first vertebra. The condyles sit on either side of the foramen magnum, the opening through which the spinal cord passes. Continue reading
Category Archives: Carnivorans
Confession time: I’m not an expert on most of the organisms I feature on Fossil Friday, and it sometimes takes me a fair bit of research to work out what I’m going to say. Because of that, when I’m swamped with other work (like this week), I will usually pick a Fossil Friday specimen that is straightforward so that I can write about it quickly. But sometimes the choice backfires. Continue reading
The deer bones I talked about a few weeks ago are part of a small assemblage from a housing development in Murrieta, in southwestern Riverside County. Among the other remains in the collection was a partial dentary (lower jaw) from a carnivore. Continue reading
In any large collection of vertebrate fossils, one of the more common specimen labels will be “unidentified bone fragment”. But even an unidentified fragment can provide useful information. Continue reading
Today is National Dog Day, and while the day is primarily honoring domestic dogs (Canis familiaris, or Canis lupus familiars), it seems fitting to also recognize their wild ancestors and cousins. Continue reading
A basic tenet of ecology is that as you move higher up a food chain, the biomass (and usually number of individual animals) will get smaller. Each trophic level in a food chain gets its energy from the level below, and since there is never a perfect 100% energy transfer there is always less energy available at higher levels. This has a profound impact on the fossil record; in general, “top-of-the-food-chain” carnivores are exceptionally rare as fossils, because they were also rare as living animals. (If you spend time outdoors, think about how many squirrels, rabbits, and deer you’ve ever seen, compared to the number of coyotes and bobcats.) While there are occasional exceptions such as the predator trap at Rancho La Brea that bias the fossil record in favor of carnivores, at most localities large carnivores are rare.
The fossils Southern California Edison El Casco Substation site are dominated by rodents, horses, and other herbivores, but a handful of large carnivores were also discovered. One of the most fascinating is the “other” Ice Age sabertooth cat, Homotherium. Continue reading
Part of the nature of paleontology is attempting to pull as much information as possible out of often very limited data. As I mentioned last week, many fossil specimens may not be especially visually compelling, but nevertheless can provide useful information. Continue reading
It happens that last Tuesday, October 6, was National Badger Day in Britain. While the European badger Meles meles does not occur in North America, why should that stop us from honoring badgers? The American badger Taxidea taxus (above at The Living Desert Zoo) is only distantly related to the European badger, but it still goes by the common name of “badger”, and that’s good enough for me!
As I’ve mentioned in several other posts, fossil carnivores are rare in the Diamond Valley Lake fauna, but they’re not completely absent. The remains tend to be isolated bone fragments, but they do reveal the presence of the particular taxon. Continue reading
While over 200,000 fossils were found at Diamond Valley Lake, only a tiny percentage of the specimens represent carnivores. This is actually to be expected; in any stable ecosystem prey animals always greatly outnumber their predators and so normally prey animals should be much more common as fossils. There are exceptions, such as “predator traps” like we see at Rancho la Brea, but in general the rare predator/common prey breakdown at Diamond Valley Lake is what we expect to find.
That said, there is actually a fairly diverse range of predators from Diamond Valley Lake, even if most of them are known only from isolated bones like as the one shown above. Continue reading