Paleontology and animal diets.

I almost called this the paleodiet as a joke.

One strange thing about paleontology I noticed is that when it comes to animal diets and ways they get food it is always black and white. Either the animal is presented as a specialist in one thing or another often to extreme, unrealistic degrees.

I saw a video on halzskaraptor and it mentioned an argument over whether that eat fish or specialize in aquatic invertebrates. Many smaller aquatic birds such as hooded mergansers and pied-billed grebes eat both.

An example animals often have diverse diets if not specialists. For example an American Robin mainly eats mainly fruit and invertebrates but will sometimes eat frogs, snakes, and fish. If a paleontologist found a fossilized Robin with a fish in its mouth the argument would be either pure piscivore or a bird that died on top of a fish due to no adaptations for fishing.

Sometimes it seems a bit odd. For example the study about whether or not alvarezsaurus species specialize in eating ants or eggs. It obviously has specialized adaptations but no arguments state how rare egg eating as a specialization is. (It is a common generalist trait but it is odd how the only specialized egg eaters I could find information on are a genus of snake in Africa and another in India). The rarity of egg specialization is odd but I Assym it is due to short breeding seasons. However that does beg the question why tropical South America lacks egg specialists or why cold climates lack egg specialists who hibernate in the cold months. However odd diets that are rare need reconsideration and asking how they can be.

Another thing is arguments on how spinosaurus feeds on fish. Is it a swimmer or a wader. Some of these get extreme. (It is the ONLY theropod I heard argued cannot swim at all and arguments that the flat tail is a minor advantage when swimming when nature works by minor advantages). Ok, that got a bit off track. But he question should be less does it wade or swim to feed but more how common or rare both is. I once seen a waterfowl documentary (I think it was called a the DUCKumentary) that showed diving ducks can dabble and dabbling ducks can dive. It is something they are not good at but they CAN do it. Degree of behavioral flexibility matters.

And maybe it is a relic of media bias but I remember a decade of T-Rex arguments on whether it is pure predator or scavenger before scientists realized most predators will scavenge and pure scavengers are rare.

In other words paleontologists often present prehistoric diets as less flexible than is common in nature.