a Toxodon, a rodent the size of an elephant. Darwin thinks it’s probably aquatic.
Many of these animals have huge hindquarters, and Darwin is impressed by Owen’s theory explaining why. In contrast to one popular view, that past trees were sufficiently large and sturdy that these creatures could climb them – imagine a sloth the size of an elephant climbing a tree, Owen theorises that these animals sat on the ground and pulled the trees down to them, in which case perfect sense would be made of their apparently clumsy skeletal structure.
Now, the only paleontological dig I’ve ever visited was mostly turning up ancient leaves, so the thought of all these fossils, just embedded in a small stretch of beach, seems rather astounding to me. It’s also a poignant reminder of how relatively unexplored natural history was in Darwin’s time – though I guess the same might well be said of the microbial world today. This is a fairly densely packed chapter – all this is just on page one!
How wonderfully the different Orders, at the present time so well separated, blended together in different points of the structure of the Taxodon!
As this able naturalist [Dr Andrew Smith] remarked to me, the carnage each day in Southern Africa must indeed be terrific!
He also describes the rheas – not the first time, certainly. While they mostly eat grass, apparently, some of them seem to go down to the lake and eat small fish. That would make a better food source, but it seems right out of character for a rattite. Some of them also go for a swim – slowly, but they can nonetheless cross a river. He mentions that the Australian explorer Charles Sturt reported seeing some emus swimming. That’s a new one on me, not that I’ve historically been very good at paying much attention to biology (more on that one later, too).
The male incubates the eggs, 20-50 at a time, from several mothers. A female can lay large numbers of eggs over a few days, but incubating them all in one go results in some of them being addled by over-incubation.
This chapter also has Darwin’s famous discovery of the lesser rhea (a.k.a. Darwin’s Rhea) – in his dinner. Fortunately, the head, neck, legs, wings, and many feathers had been preserved.
One final note I will make on this chapter, is a cute little reference to the Genesis creation story.
I found only one little toad (Phryniscus nigricans) which was most singular from its colour… If an unnamed species, surely it ought to have been called Diabolicus, for it is a fit toad to preach in the ear of Eve.