Turtle shell in the context of "Hanzi"

Oracle bone script is the oldest attested form of written Chinese, dating to the late 2nd millennium BC. Inscriptions were made by carving characters into oracle bones, usually either the shoulder bones of oxen or the plastrons of turtles. The writings themselves mainly record the results of official divinations carried out on behalf of the Late Shang royal family. These divinations took the form of scapulimancy where the oracle bones were exposed to flames, creating patterns of cracks that were then subjected to interpretation. Both the prompt and interpretation were inscribed on the same piece of bone that had been used for the divination itself.

Out of an estimated 150,000 inscriptions that have been uncovered, the vast majority were unearthed at Yinxu, the site of the final Shang capital (modern-day Anyang, Henan). The most recent major discovery was the Huayuanzhuang cache found near the site in 1993. Of the 1,608 Huayuanzhang pieces, 579 bear inscriptions. Each of the last nine Shang kings are named in the inscriptions beginning with Wu Ding, whose accession is variously dated between 1250 and 1200 BC. Oracle bone inscriptions corresponding to Wu Ding's reign have been radiocarbon dated to 1254–1197 BC (±10 years). Following the overthrow of the Shang by the Zhou dynasty in c. 1046 BC, divination using milfoil became more common; far fewer oracle bone inscriptions are dated to the Western Zhou. No Zhou-era sites with a comparable cache of inscriptions to Yinxu have been found; however, examples from this period appear to be more widespread, having been found near most major population centers. New sites have continued to be discovered since 2000.

An exoskeleton (from Ancient Greek έξω (éxō) 'outer' and σκελετός (skeletós) 'skeleton') is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. that of a human) which is enclosed underneath other soft tissues. Some large, hard and non-flexible protective exoskeletons are known as shell or armour.

Examples of exoskeletons in animals include the cuticle skeletons shared by arthropods (insects, chelicerates, myriapods and crustaceans) and tardigrades, as well as the skeletal cups formed by hardened secretion of stony corals, the test/tunic of sea squirts and sea urchins, and the prominent mollusc shell shared by snails, clams, tusk shells, chitons and nautilus. Some vertebrate animals, such as the turtle, have both an endoskeleton and a protective exoskeleton.

Turtles (order Testudines) are reptiles characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water.

Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates that join up to cover the body. Turtles are ectotherms or "cold-blooded", meaning that their internal temperature varies with their direct environment. They are generally opportunistic omnivores and mainly feed on plants and animals with limited movement. Many turtles migrate short distances seasonally. Sea turtles are the only reptiles that migrate long distances to lay their eggs on a favored beach.

The jaguar (Panthera onca) is a large cat species and the only living member of the genus Panthera that is native to the Americas. With a body length of up to 1.85 m (6 ft 1 in) and a weight of up to 158 kg (348 lb), it is the biggest cat species in the Americas and the third largest in the world. Its distinctively marked coat features pale yellow to tan colored fur covered by spots that transition to rosettes on the sides, although a melanistic black coat appears in some individuals. The jaguar's powerful bite allows it to pierce the carapaces of turtles and tortoises, and to employ an unusual killing method: it bites directly through the skull of mammalian prey between the ears to deliver a fatal blow to the brain.

The modern jaguar's ancestors probably entered the Americas from Eurasia during the Early Pleistocene via the land bridge that once spanned the Bering Strait. Today, the jaguar's range extends from the Southwestern United States across Mexico and much of Central America, the Amazon rainforest and south to Paraguay and northern Argentina. It inhabits a variety of forested and open terrains, but its preferred habitat is tropical and subtropical moist broadleaf forest, wetlands and wooded regions. It is adept at swimming and is largely a solitary, opportunistic, stalk-and-ambush apex predator. As a keystone species, it plays an important role in stabilizing ecosystems and in regulating prey populations.

A dermal bone or investing bone or membrane bone is a bony structure derived from intramembranous ossification forming components of the vertebrate skeleton, including much of the skull, jaws, gill covers, shoulder girdle, fin rays (lepidotrichia), and the shells of turtles and armadillos. In contrast to endochondral bone, dermal bone does not have a cartilage precursor, and it is often ornamented. Dermal bone is formed within the dermis and grows by accretion only – the outer portion of the bone is deposited by osteoblasts.

The function of some dermal bone is conserved throughout vertebrates, although there is variation in shape and in the number of bones in the skull roof and postcranial structures. In bony fish, dermal bone is found in the fin rays and scales. A special example of dermal bone is the clavicle. Some of the dermal bone functions regard biomechanical aspects such as protection against predators. The dermal bones are also argued to be involved in ecophysiological implications such as the heat transfers between the body and the surrounding environment when basking (seen in crocodilians) as well as in bone respiratory acidosis buffering during prolonged apnea (seen in both crocodilians and turtles). These ecophysiological functions rely on the set-up of a blood vessel network within and straight above the dermal bones.