One day in the late Eocene, a jaguar prowled through a bamboo thicket on the Caribbean island of Hispaniola. As the cat padded by, several seeds snagged onto its fur with their tiny hooks, a dispersal trick that often carried the seeds to fertile ground. This time, however, their free ride ended in a pool of resin, and immortality of a sort. Irritated by the seeds’ spiky hooks, the cat rubbed against the trunk of a Hymenaea tree, a great resin producer of the American and African tropics. A wound in the tree’s bark oozed a puddle of the sticky stuff, and by chance the cat left a tuft of fur and one of the annoying grass seeds in the goo. Later, another flow of resin spilled over the fur and seed, sealing both in what would prove to be one of nature’s ultimate time capsules.
Tens of millions of years later the resin, still encapsulating the fur and seed, would surface again, now hardened into the fossil called amber. A miner tunneling into one of the Dominican Republic’s amber mines recovered this nodule, and the specimen eventually found its way into the hands of paleoentomologist George Poinar at the University of California at Berkeley.
Poinar’s passion for amber has nearly outgrown his office. His shelves are jammed with plastic bags of amber waiting to be sorted; photos of favorite amber specimens decorate his office walls; and a map of the Caribbean is centered squarely over his desk. It’s not difficult to understand why Poinar is so enamored: each piece of amber forms an exquisite crystalline world, often filled with fragile insects, flowers, and bits of moss.
To display his discoveries, Poinar prefers the detail of photomicrographs, and in one such blowup the cat hair and seed are clearly visible. It’s a rare find, Poinar says. Through the resin’s golden window, the seed’s tenacious hooks look burnished and surreal, like a kind of giant, mutant Velcro grasping the spiky tuft of hair. We can’t say absolutely that the animal was a jaguar, Poinar says, but we analyzed the hair with a high-resolution microscope, and it came out as a carnivore, not a rodent--the first evidence of carnivores in that forest. And it very well could have been a jaguar, since there are reports of grass spikelets exactly like this one being found on jaguars in South America today.
These particular species of carnivore and bamboo are now extinct on Hispaniola, the large Caribbean island that encompasses both the Dominican Republic and Haiti. Therefore this amber-embalmed specimen offers a unique snapshot of a lost world. Together with similar specimens, it presents a rare opportunity to piece together--in great detail--what this small corner of Earth looked like 40 million to 25 million years ago. It was then a forest of tall, broad-leaved evergreens whose trunks glistened with shiny ribbons of resin. Beetles and termites scuttled under the bark, seeking the rich food of decaying wood; small reptiles crawled up and down the trunks, looking for food; ants paraded overhead, carrying bits of dead insects or leaves; nearby swarmed bees, flies, and midges. From time to time these unwary denizens--along with everything from feathers to flowers to frogs--would become trapped in the resin that served as the trees’ first line of defense against destructive insects. Because of the resin’s remarkable embalming powers, nearly all of these specimens--so many of which now adorn Poinar’s office--are displayed in their full three- dimensional glory.
