Descent and Decline

Not much phased Proganochelys. Equipped with neck and tail spines in addition to thick plates of armor, this Mesozoic monster even wielded a spiked club at the end of its tail. No wonder the earliest known turtle had no need for neck retraction.

Certain traits did foreshadow the form of future tortoises. Large otic openings flanked the head. Carapace and plastron armor consisted of fused dermal bone connected to the ribs. Sprawling legs emerged from fenestrae on the corners of the torso.

But only one major evolutionary event was to further alter the morphological character of the Order Testudines. Approximately 50 million years after the known specimen of Proganochelys roamed the earth, which was transpiring about 210 million years ago, turtles split into two major phylogenetic groups, the pleurodires and cryptodires. Pleurodires are side-necked tortoises. Most extant pleurodires are indigenous to Asia. In contrast, cryptodires retract their neck as one normally expects of a turtle -- they pull it in straight. The true distinction between the two groups lies in the mechanics of the jaw adductor muscle.

For many years, paleontologists speculated that turtles represent the only surviving anapsids, or vertebrates without holes in the sides of their skulls. This viewpoint was revised in recent years. Scientists realized that previous studies implicitly assumed that since turtles don't have cranial holes (temporal fenestrae), they must be most closely related to anapsids. Instead, it was proposed, why not test a phylogenetic reconstruction where turtles are a branch of the diapsids (vertebrates with two temporal fenestrae on either side of the skull) that had filled in the fenestrae? Genomic studies quickly confirmed this hypothesis, and turtle were grouped with the extinct pareiasaurs near the lepidosauromorphs (lizards).

Almost 300 million years after turtles lumbered onto the stage of life, most living species are on the brink of disappearing. Many have already passed, in our lifetimes. In southeast Asia, the situation is most dire, with over half of 90 native species threatened with imminent extinction.

The Asian turtles' predicament is driven by the newfound prosperity of China. Demanded as an ingredient for food and traditional medicine, the price fetched by chelonians has skyrocketed throughout southeast Asia. The growth of the problem has accelerated for almost 25 years. The pace of the acceleration quickened in the 1990s when the yuan became easier to convert to other currencies. To quote a New York Times article from eight years ago, "In the marketplace, the price of a single turtle can range from a few dollars to more than a thousand. The three-striped box turtle, or Cuora trifasciata, from Vietnam has a reputation among the Chinese as a cure for cancer, and Dr. Kiester said a Vietnamese collector could sell one to a dealer for $1,200 -- about six times the average annual income. As a result, that turtle has become extremely rare."

Herpetologists find more turtles at restaurants than in the wild, even in national parks. "The high value of wild-caught turtles has turned much of the rural populace of Southeast Asia into a kind of enormous net of collectors, making it almost impossible for researchers to see turtles first. For example, Dr. Platt said he considered himself lucky to have seen two Sulawesi Forest Turtles in the wild, a first for a Western biologist, though the species was readily available for sale."

Most humans are ignorant of or impassive about the fate of turtles, but not everyone has stayed complacent during the slaughter. Richard Ogust, a writer from Manhattan, metamorphosed into an activist after visiting China and observing the travesty firsthand. Eventually, Ogust accumulated 1,200 rescued turtles in his penthouse.

A highly acclaimed documentary recently aired on PBS tracks Ogust. Although I have not yet seen the movie, titled The Chances of the World Changing, an online summary informed me of Ogust's life during the filming. Unable to care for his vast number of turtle tenants, Ogust started developing a nonprofit institute dedicated to breeding and safeguarding freshwater turtles and tortoises that would also provide space for his collection. But property deals failed to materialize, and the institution could not get on its feet; public lauding never transformed into monetary support. Forced out of his penthouse, Ogust pitched a tent beside the warehouse that now housed his turtles, in New Jersey. Ultimately, the turtles were dispersed to a variety of preservationists across the country.

Turtle farming, a growing practice throughout China, is flourishing as turtles disappear in the wild. But farming fails to stem the tide of illegal harvesting, and most varieties of turtles are economically infeasible to farm, due to their long periods of maturation. The only true solution is environmental activism. Hopefully, a core of educated Asians can eventually change the tastes of their brethren. Maybe those great chelonian monuments of evolution can exist beyond my lifetime as something beside future fossils.