Scholars express doubt as to the ultimate origin of Cosmatesque paving, an ornate style of decoration on the floors of certain medieval Italian churches. Such floors are comprised of polished stone parallelograms, roundels and other geometric patterns, often enlivened with coiling bands of smaller mosaic tesserae. These designs are polychrome, assembled from alabaster, purplish-red porphyry, green serpentine, and orange-yellow giallo antico. Stones fit together in these floors are polished to a fine sheen – the floors have a hard and brilliant gem-like aspect. It is like walking on agate and the complex geometric patterns repeating underfoot make transit of such surfaces a vertiginous affair – the bright stones either seem foreground or background, and the paving oscillates between these two readings creating, in some cases, an effect like Op Art.
Most descriptions of this paving attribute its triumphal appearance in the latter half of 12th century to a family of craftsmen, the Cosmati said to hail from Agnani, a village 37 miles from Rome. Lorenzo Cosmati was said to have learned his technique from Greeks and, indeed, the floors of Roman churches attributed to him have a Byzantine aspect. In Byzantium, mosaic work flourished and some writers believe that the floors in Christian churches were designed to simulate the abstract, non-figurative designs in Turkish and Persian rugs, textiles used as prayer mats in Muslim mosques and otherwise familiar in the Eastern Empire. Certainly, fine Turkish and Persian rugs have a reverie-inducing quality arising from the eye’s perception of certain repeated patterns as either advancing or retreating into the fabric. These qualities exist in Byzantine mosaic as well. However, Byzantine mosaic, generally, employs smaller elements and considerably more gold leaf and colored glass than is the case in the Cosmatesque floors in Rome and throughout Italy. (The greatest example of Byzantine "Cosmatesque" is said to be the Palatine Chapel in Palermo, a place that I have visited – in my view, the transfiguration of every surface in the grotto-like chapel with innumerable gold tesserae is very different in appearance and effect than the paving in the Italian churches that I have seen. Sicilian and Byzantine Cosmatesque paving, cloister frieze and architrave decoration seems more closely related to me to the Roman opus sectile used on the floors of banqueting halls and bedrooms in pre-Christian Roman villas.) In any event, the claim that Lorenzo Cosmati "invented" the form of decorative paving visible in Roman churches in the 12th and 13th century is complicated by the fact that archetypical Cosmatesque floors are found in Monte Cassino, an abbey built a hundred years earlier. Furthermore, there is some question as to whether the name for this style of floor relates to an actually family of craftsmen or is a serendipitous conflation of an Italian family name ("Cosmati") with the Greek word cosmos, meaning in the 12th century a luminous and beautiful ordered place or thing. An alternative term for paving of this kind is Cosmedin, clearly a world related to "cosmetic," and more obviously invoking the idea that flooring of this kind created a kind of glistening and geometrically rigorous "cosmos", an opening beneath our feet into an order of clarity, beauty, serenity, made from enduring stone.
Furthermore, the exact quality of the Roman Cosmatesque arises from the unique nature of the building elements used to create those floors. Visitors to Rome’s Pantheon, the sole surviving structure from the great age of pagan architecture and a monument to the power of the Caesars, stand astonished by the riot of colors on display in the vast temple’s interior. Roman architects of the age of the Caesars luxuriated in using marbles and stone of exotic texture and color – indeed, quarries were established throughout the empire to provide polychrome stone for use in the capitol. Africa and Asia Minor, even India, seem to have been sources for the lavish silky marble used for monumental elements in Roman palaces and temples. And after Rome’s decline and fall, these building materials were strewn throughout the landscape in the small city surviving in the ruins of the great capitol. Much of the marble in the Forum and on the Palatine and Capitoline hills was hacked apart and burned for lime. But the huge columns of granite and porphyry proved resistant and, in the 12th century, could be sawn into disk-like roundels, these cross-sections gear-shaped because of their fluting, then, embedded in the Cosmatesque floors. As a result, much of these pavement, like cross-sections of tissue embedded in a histology slide, is assembled from the wreckage of the great pagan temples and public buildings that once adorned the Seven Hills of Rome. The gem-like qualities of the stone and its abundance testifies to the vastness and ruinous splendor of the ancient ruins from which these floors were built.
It is the grave misfortune of the Plowshare Tortoise (astrochelys yniphora) that the dome of its shell closely resembles a gorgeously designed Cosmatesque floor. This animal, sometimes called the Angonaka tortoise, lives in a small part of Madagascar, a dry deciduous forest and savannah in the vicinity of Baly Bay on the northwest coast of the island – their native range seems to be an area less than 20 miles square. Since its discovery, the tortoise has been prized for the astonishing beauty of its carapace – the term "astrochelys" describes the star-shaped patterns of interlocking shell that comprise the animal’s carapace. The shell is highly convex ("chelys" means "convex") and symmetrically patterned with polished-looking mahogany and brandy-colored plates. The creature is one of the most beautiful animals on earth. Chinese collectors have offered as much as $60,000 for a single specimen – a kind of living and ornate gemstone to place in their gardens.
Astrochelys yniphora is popularly called "Ploughshare" because of a protruding gular scute on the animal’s plastron. To understand this anatomical feature, we must learn some technical terms relating to turtles. "Scutes" are the keratinous plates fused together to comprise the shell of a turtle – terrapins, tortoises, and turtles are all animals of the testudines order, that is, "turtles." The convex dome on the animal’s dorsal side is called the "carapace." The flat armor on the belly of turtle is named the "plastron." As is the case with the carapace, the plastron of a turtle is comprised of a number of scutes. Those scutes directly underlying the turtle’s head – the so-called "anterior scutes" – are called "gular." In a Ploughshare tortoise, the gular scute protrudes, jutting forward under the animal’s head like a trowel. Male Ploughshare tortoises fight for the privilege of breeding – in this combat, the male tortoises seek to overturn their adversaries, using their gular scutes as battering rams and pry bars. The tortoises are not large – they grow to about 18 inches long. In their native range, Ploughshare tortoises eat dried bamboo and bamboo leaves (they have never been observed to eat green or living bamboo); they also feed on the sun-dried feces of other reptiles and small carnivores.
Tortoises live in slow-motion. A Ploughshare tortoise is not sexually mature until it is 20 years old. This is a long time for an animal threatened on all sides with extinction. First, the Madagascar savannas are infested with feral "bush pigs". These pigs have a taste for turtle eggs and root up and devour clutches of them that they discover. The local farmers use slash and burn methods of agriculture, husbandry that is lethal to the slow-moving tortoises. But, most importantly, tortoise smuggling is rife – criminal gangs hunt for the tortoises and capture them to be sold to wealthy Malaysian and Chinese collectors. As a consequence of these factors, the Ploughshare tortoise is severely endangered and, indeed, almost extinct – it is estimated that only 500 or so individuals survive in the wild. (Fifty-four Ploughshare tortoises, together with another two dozen "Radiated" turtles, an animal that is a close cousin to Astrolychus Yniphora, were confiscated from smugglers at an international airport in Thailand; it is conjectured that these smugglers were in possession of about one-tenth of the population of Angonaka tortoises living wild in the world.) Tortoises have tiny brains and incapable to adapting to changes in their environment – in the 17th century, a zoologist removed the brain of a tortoise: the animal lived for six months without its. The same zoologist lopped of the head of one of his specimens – that animal continued breathing and walking about headlessly for 23 days.
During the war in Vietnam, military officials were alleged to have remarked: "We had to destroy that village to save it." Something similar might be said about the Ploughshare tortoises currently surviving in the wild – the scientists attempting to conserve the species have taken to disfiguring the animals to protect them from being collected by smugglers. On You-Tube, an interested person can watch veterinarians and conservationists perching tortoises on round pedestals, the kind of wooden spools around which cable is wrapped. The tortoises’ feet don’t touch the ground as the animals balance on their plastrons on the spool. Clawed feet paw at the air helplessly as scientist’s use power tools to chisel letters into the gorgeous Cosmatesque shells of the animals. Typically, conservationists number each tortoise with big, ugly numerals and, then, grind letters into the shell labeling the quadrant of the park were the turtle was collected. In this way, the turtles are rendered unsuitable for sale in the Asian markets that prize the animals.
The conservationists mutilating the shells of these beautiful animals act from desperation. And, of course, they are not immune to the startling architectronic splendor of the animal’s carapace and plastron. "It is a matter of last resort," one of the zoologists says and one can hear the tone of tragic resignation in his voice. When the gods taught Orpheus music, they first showed him how to stretch cords across the hollow of a turtle’s shell in order to make a lyre. The alternative name to Testudines is Chelys – Chelys not only means "convex" but is also the Greek word for "lyre".