Darwin’s miniature primeval monsters
From the archive, 3 October 1838: Darwin’s miniature primeval monsters
Marine iguanas found by Darwin on the Galapagos Islands confirm the existence of sea-dwelling dinosaurs
The following passage from Lyell’s Elements of Geology may startle many - an account of miniature primeval monsters yet existing in
“Some bright little isles of their own, In a blue summer ocean far off and alone.”
The author has been describing the gigantic creatures whose fossils attest their existence. “For the last twenty years’ anatomists have agreed that these extinct saurians must have inhabited the sea, although no living reptile was known. They argued, that, as there are now chelonians, like the tortoise, living in fresh water, and others, as the turtle, frequenting the ocean, so they may have been formerly some saurians proper to salt, others to fresh water. The recent discovery, however, of a maritime saurian has now rendered it unnecessary to speculate on such possibilities.
“This creature was found in the Galapagos Islands, during the visit of H. M. S. Beagle to that archipelago in 1835; and its habits were then observed by Mr. Darwin. The islands alluded to are situated under the equator, nearly six hundred miles on the westward of the coast of South America. They are volcanic, some of them being three thousand or four thousand feet high; and one of them, Albemarle Island, seventy-five miles long. The climate is mild, very little rain falls, and, in the whole archipelago, there is only one rill of fresh water that reaches the coast. The soil is for the most part dry and harsh, and the vegetation scanty.
“The birds, reptiles, plants, and insects, are, with very few exceptions, of species found nowhere else in the world, although all partake in their general form of an American character. Of the Mammalia, says Mr. Darwin, one species alone appears to be indigenous - a large and peculiar kind of mouse; but the great number of lizards, tortoises, and snakes is so great, that it may be called a land of reptiles. The variety, indeed, of species is small; but the individuals of each are in wonderful abundance. There is a turtle, a large tortoise (Testudo indicus), four lizards, and about the same number of snakes, but no frogs or toads.
“Two of the lizards belong to the family Iguanidae of Bell, and to a peculiar genus (Amblyrhynchus) established by that naturalist, and so named for their obtusely truncated head and short snout. Of these lizards, one is terrestrial in its habits, and burrows in the ground, swarming everywhere on the land - having a round tail and a mouth somewhat resembling in form that of the tortoise; the other is aquatic, and has its tail flattened laterally for swimming.
“This marine saurian, says Mr. Darwin, ‘is extremely common on all the islands throughout the archipelago. It lives exclusively on the rocky sea-beaches, and I never saw one even ten yards in-shore. The usual length is about a yard, but there are some even four feet long. It is of a dirty black color; sluggish in its movements on the land, but, when in the water, it swims with perfect ease and quickness, by a serpentine movement of its body and flattened tail, the legs during this time being motionless, and closely collapsed on its sides. Their limbs and strong claws are admirably adapted for crawling over the rugged and fissured masses of lava which everywhere form the coast. In such situations a group of six or seven of these hideous reptiles may oftentimes be seen on the black rocks, a few feet above the surf, basking in the sun with outstretched legs.”