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68-590: Lepidochelys kempii Lepidochelys olivacea Ridley sea turtles are a genus ( Lepidochelys ) of sea turtle comprising two species: Kemp's ridley sea turtle and the olive ridley sea turtle . Kemp's ridley sea turtles are currently on the New York and United States lists of endangered species. Adult ridley sea turtles grow to a length of 51–71 cm (20–28 in), and weight of 36–50 kg (79–110 lb). They feed on crabs , fish , cephalopods , clams, and some marine vegetation. The origin of "ridley"

136-410: A beak . Kemp's ridley turtle adults reach a maximum of 75 cm (30 in) in carapace length and weighing a maximum of 50 kg (110 lb). The adult's oval carapace is almost as wide as it is long and is usually olive-gray in color. The carapace has five pairs of costal scutes. In each bridge adjoining the plastron to the carapace are four inframarginal scutes, each of which is perforated by

204-433: A complete bony plastron and an incomplete carapace. The fossil showed that the plastron evolved before the carapace. Like crown turtles, it lacked intercostal muscles, so rib mobility was limited. The ribs were laterally expanded and broadened without ossification, like the embryos of modern turtles. The development of a shell reaches completion with the late Triassic Proganochelys of Germany and Thailand. It lacked

272-418: A few Kemp's ridley nests. Plastron The turtle's shell is an important study, not just because of the apparent protection it provides for the animal but also as an identification tool, in particular with fossils, as the shell is one of the likely parts of a turtle to survive fossilization. Hence understanding the shell structure in living species provides comparable material with fossils. The shell of

340-516: A fully developed carapace and a relocated rib cage. The theory accounted for the evolution of fossil pareisaurs from Bradysaurus to Anthodon , but not for how the ribs could have become attached to the bony dermal plates. Recent stem-turtle fossil discoveries provide a "comprehensive scenario" of the evolution of the turtle's shell. A fossil that may be a stem-turtle from the Permian of South Africa, Eunotosaurus , some 260 million years ago, had

408-480: A nest along the Florida Panhandle on June 26, 2010, and brought to a temperature-controlled warehouse at NASA's Kennedy Space Center , where 56 hatched, and 22 were released on 11 July 2010. The overall plan was to collect eggs from about 700 sea turtle nests, incubate them, and release the young on beaches across Alabama and Florida over a period of months. Eventually, 278 nests were collected, including only

476-436: A pore. The head has two pairs of prefrontal scales. These turtles change color as they mature. As hatchlings, they are almost entirely a dark purple on both sides, but mature adults have a yellow-green or white plastron and a grey-green carapace . Kemp's ridley has a triangular-shaped head with a somewhat hooked beak with large crushing surfaces. The skull is similar to that of the olive ridley . Unlike other sea turtles,

544-740: A record of 128 Kemp's ridley sea turtle nests on Texas beaches, including 81 on North Padre Island ( Padre Island National Seashore ) and four on Mustang Island . The figure was exceeded in each of the following 7 years (see graph to 2013, provisional figures for 2014 as at July, 118. ). Wildlife officials released 10,594 Kemp's ridley hatchlings along the Texas coast in 2007. The turtles are popular in Mexico as raw material for boots and as food. In July 2020, five rehabilitated turtles were released back in to Cape Cod with satellite tracking devices to monitor their wellbeing. A 2020 rescue mission to save 30 turtles from

612-489: A season, keeping 10 to 20 days between nestings. Incubation takes 6–8 weeks. Around 100 eggs are in a clutch . The hatchlings' sex is decided by the temperature in the area during incubation . If the temperature is below 29.5 °C, the offspring will be mainly male. Kemp's ridley sea turtle is currently listed as endangered under the Endangered Species Act (ESA). Egg harvesting and poaching first depleted

680-444: A short broad trunk, and a body-case of broadened and somewhat overlapping ribs, suggesting an early stage in the acquisition of a shell. The fossil has been called "a diapsid reptile in the process of becoming secondarily anapsid". Olivier Rieppel summarizes the phylogenetic origins of the ancestral turtles: " Eunotosaurus is placed at the bottom of the stem section of the turtle tree, followed by Pappochelys and Odontochelys along

748-422: A single undivided gular scute. The gular scutes may be referred to as a gular projection if they stick out like a trowel . The plastral formula is used to compare the sizes of the individual plastral scutes (measured along the midseam). The following plastral scutes are often distinguished (with their abbreviation): Comparison of the plastral formulas provides distinction between the two species. For example, for

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816-618: Is April to August. They nest mostly (95%) on a 16-mile beach in the Mexican state of Tamaulipas and on Padre Island in the US state of Texas, and elsewhere on the Gulf Coast. They mate offshore. Gravid females land in groups on beaches in arribadas or mass nesting. They prefer areas with dunes , or secondarily, swamps . The estimated number of nesting females in 1947 was 89,000, but shrank to an estimated 7,702 by 1985. Females nest one to four times during

884-486: Is a Spanish word for "arrivals". Males will typically stay closer to breeding grounds. Juvenile turtles tend to live in floating sargassum seaweed beds for their first years. Then, they range between northwest Atlantic waters and the Gulf of Mexico while growing into maturity. They reach sexual maturity at the age of 10–12. This is the only species that nests primarily during the day. The nesting season for these turtles

952-624: Is a subject of speculation. Prior to being known as ridleys, French naturalist Bernard Germain de Lacépède referred to the Lepidochelys species as "bastard turtles." Renowned sea turtle conservationist Archie Carr claimed that "ridley" was a common Floridan term, quite possibly, a dialectal corruption of "riddle." The Kemp's ridley sea turtles were on the brink of extinction in the 1960s with low numbers of 200 nesting individuals. Due to strict laws that protected their nesting sites in Mexico and altered fishing gear to avoid accidental capture of

1020-455: Is apparent in both sections of the shell, carapace, and plastron, and is thicker in critical areas. A thicker epidermis allows a higher stress force to be experienced without permanent deformation or critical failure of the shell. The shape of the shell is from its evolutionary process, which caused many microstructures to appear to aid survival and motion. Shell shape allows the animal to escape predatory situations. Microstructures can include

1088-466: Is called Kemp's ridley because Richard Moore Kemp (1825–1908) of Key West was the first to send a specimen to Samuel Garman at Harvard , but the origin of the name "ridley" itself is unknown. Prior to the term being popularly used (for both species in the genus), L. kempii at least was known as the "bastard turtle". At least one source also refers to Kemp's ridley as a "heartbreak turtle". In her book The Great Ridley Rescue , Pamela Philips claimed

1156-408: Is estimated to be 9.9% of the nest estimate of 1947. One mechanism used to protect turtles from fishing nets is the turtle excluder device (TED). It is a grid of bars with an opening at the top or bottom, fitted into the neck of the shrimp trawl. It works by allowing small animals to slip through bars and get caught, while sea turtles strike the bars and are ejected through an escape hole on either

1224-667: Is one of two living species in the genus Lepidochelys (the other one being L. olivacea , the olive ridley sea turtle ). The species L. kempii primarily occupies habitat around the Gulf of Mexico, though its migrations into the Atlantic Ocean are being affected by rising temperatures. Kemp's ridley sea turtle is listed as endangered under the Endangered Species Act (ESA), and conservation efforts are attempting to rebuild population numbers. Human activity, including but not limited to habitat destruction , climate change, and oil spills, threaten populations. This species of turtle

1292-609: Is variability in feeding habits due to habitat differences and maturation of the turtles. Variation in habitat region as well as prey availability were found to alter diet composition. Regional diet compositions aid in conservation efforts through enabling predicting food sources becoming affected by major events. Most females return each year to a single beach—Rancho Nuevo in the Mexican state of Tamaulipas —to lay eggs . The females arrive in large groups of hundreds or thousands in nesting aggregations called arribadas , which

1360-495: The eastern box turtle , the plastral formula is: an > abd > gul > pect > hum >< fem. Turtle plastrons were used by the ancient Chinese in a type of divination called plastromancy . See also Oracle bones . The turtle's shell is covered in scutes that are made of keratin . The individual scutes as shown above have specific names and are generally consistent across the various species of turtles. Terrestrial tortoises do not shed their scutes. New scutes grow by

1428-408: The hawksbill turtle , among other species, has been used as a material for a wide range of small decorative and practical items since antiquity, but is normally referred to as tortoiseshell . The turtle shell is made up of numerous bony elements, generally named after similar bones in other vertebrates, and a series of keratinous scutes which are also uniquely named. The ventral surface is called

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1496-424: The osteoid , and the periosteum . The evolution of the plastron has remained more mysterious, though Georges Cuvier, a French naturalist and zoologist in the 19th century, wrote that the plastron developed primarily from the sternum of the turtle. This fits well with the knowledge obtained through embryological studies, showing that changes in the pathways of rib development often result in malformation or loss of

1564-467: The plastron . These are joined by an area called the bridge. The actual suture between the bridge and the plastron is called the anterior bridge strut. In Pleurodires the posterior pelvis is also part of the carapace, fully fused with it. This is not the case in Cryptodires which have a floating pelvis. The anterior bridge strut and posterior bridge strut are part of the plastron. On the carapace are

1632-546: The 456 oiled turtles that were rescued, cleaned, and released by the US Fish and Wildlife Service were Kemp's ridleys. Of the endangered marine species frequenting Gulf waters, only Kemp's ridley relies on the region as its sole breeding ground. As part of the effort to save the species from some of the effects of the Deepwater Horizon oil spill, scientists took nests and incubated them elsewhere; 67 eggs were collected from

1700-1073: The African coast from Morocco to Cameroon involve unverified specimens and may include misidentified L. olivacea . In November 2021 a male was found alive on Talacre beach in North Wales . The turtle was taken to the Anglesey Sea Zoo for treatment, with the intent of eventual transportation back to the Gulf of Mexico. Kemp's ridley turtle feeds on mollusks , crustaceans (such as floating crabs and shrimp ), jellyfish , fish , algae or seaweed , and sea urchins . Juveniles primarily are pelagic surface-feeders, while adults are opportunistic bottom-feeders that feed primarily on crabs. Research has shown that dives made by these turtles, including those made to forage, may be longer at night. Comparing dietary habits of head-started turtles (turtles raised in captivity before release) and wild turtles found little difference in variance in feeding habits, but there

1768-724: The American Northeast and are subjected to late-season storms. Some Kemp's ridleys were airlifted from Mexico after the 1979 blowout of the Ixtoc 1 rig, which spilled millions of gallons of oil into the Gulf of Mexico. Since April 30, 2010, 10 days after the accident on the Deepwater Horizon , 156 sea turtle deaths were recorded; most were Kemp's ridleys. Louisiana Department of Wildlife and Fisheries biologists and enforcement agents rescued Kemp's ridleys in Grand Isle . Most of

1836-531: The Gulf of Mexico and only 2-4% from the Atlantic are adults. Juveniles and subadults, in contrast, regularly migrate into the Atlantic Ocean and occupy the coastal waters of the continental shelf of North America from southern Florida to Cape Cod , Massachusetts, and occasionally northward. The time periods of these migrations appear to be growing longer due to rising sea temperatures. Accidental and vagrant records are known with some regularity from throughout

1904-465: The Kemp's ridley, their numbers have increased to estimated an 7000–9000 nesting individuals today. The olive ridley sea turtle is considered to have the most abundant numbers today, estimated as 800,000 nesting individuals. The threats to their survival are loss of nesting habitat, direct harvest of the eggs and adults, and entanglement in fishing gear. Laws against harvesting the adults and eggs also have helped

1972-415: The ability to pull its head into its shell, and had a long neck and a long, spiked tail ending in a club, somewhat like an ankylosaur . Septicemic cutaneous ulcerative disease (SCUD) or "shell rot" causes ulceration of the shell. This is caused by bacteria or fungi entering through an abrasion , and poor animal husbandry . The disease progresses to a septicemic infection causing the degradation of

2040-413: The addition of keratin layers to the base of each scute. Aquatic chelonii shed individual scutes. The scute effectively forms the skin over the underlying bony structures; there is a very thin layer of subcutaneous tissue between the scute and the skeleton. The scutes can be brightly colored in some species, and turtle shells often follow Thayer's law with carapace usually being a darker patterning than

2108-420: The bridge of the shell. The plastron is made up of nine bones and the two epiplastra at the anterior border of the plastron are homologous to the clavicles of other tetrapods. The rest of the plastral bones are homologous to the gastralia of other tetrapods. The plastron has been described as an exoskeleton , like osteoderms of other reptilians; but unlike osteoderms, the plastron also possesses osteoblasts ,

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2176-413: The carapace represents transformed vertebrae and ribs. While other tetrapods have their scapula, or shoulder blades , found outside of the ribcage, the scapula for turtles is found inside the ribcage. The shells of other tetrapods, such as armadillos , are not linked directly to the vertebral column or rib cage allowing the ribs to move freely with the surrounding intercostal muscle. However, analysis of

2244-558: The coast of southern Tamaulipas, to survey and instigate conservation plans. And in the United States, Kemp's ridley turtle was first listed under the Endangered Species Conservation Act of 1970 on December 2, 1970, and subsequently under the Endangered Species Act of 1973. In 1977 an informal, binational multiagency, the Kemp's Ridley Working Group, first met to develop a recovery plan. A binational recovery plan

2312-445: The dermal bone. The spine and expanded ribs are fused through ossification to dermal plates beneath the skin to form a hard shell. Exterior to the skin the shell is covered by scutes , which are horny plates made of keratin that protect the shell from scrapes and bruises. A keel , a ridge that runs from front to the back of the animal is present in some species, these may be single, paired or even three rows of them. In most turtles

2380-457: The dermis, osteoderms , fused first to each other and then to the ribs beneath them. The theory persisted into the 21st century, when Olivier Rieppel proposed a hypothetical turtle precursor, its back covered by bony armour plates in the dermis, which he called the "Polka Dot Ancestor". Michael Lee proposed that the transformation of the carapace began with an unarmoured parareptile and then an armoured pareiasaur, and ended with modern turtles with

2448-425: The development of the turtle embryo , the ribs grow sideways into the carapacial ridge, unique to turtles, entering the dermis of the back to support the carapace. The development is signalled locally by fibroblast growth factors including FGF10 . Zoologists have sought to explain the evolutionary origin of the turtles, and in particular of their unique carapace. In 1914, J. Versluys proposed that bony plates in

2516-421: The edge of the shell are 12 pairs of marginal scutes. All these scutes are aligned so that for the most part the sutures between the bones are in the middle of the scutes above. At the anterior of the shell there may be a cervical scute (sometimes incorrectly called a nuchal scute) however the presence or absence of this scute is highly variable, even within species. On the plastron there are two gular scutes at

2584-408: The evolution from amphibians to terrestrial amniotes, transition in a wide variety of skin structures occurred. Ancestors of turtles likely diverged from amphibians to develop a horny cover in their early terrestrial ancestral forms. The carapacial ridge plays an essential role in the development of the turtle shell. Embryological analyses show that the carapacial ridge initiates the formation of

2652-410: The fossil specimens which show forked ends. This evidence shows a gradual change from paired gastralia, to paired and fused gastralia, and finally to the modern plastron across these three specimens. In certain families there is a hinge between the pectoral and abdominal scutes allowing the turtle to almost completely enclose itself. In certain species the sex of a testudine can be told by whether

2720-400: The freezing seas of Cape Cod was delayed by weather and technical issues, spurring a temporary rescue mission en route between Massachusetts and New Mexico. The Tennessee Aquarium offered overnight shelter and care, and the turtles were eventually released to the sea. These cold-stunning events may become more common with rising sea temperatures, as juveniles linger in near-shore waters in

2788-455: The front half of the plastron and the hyoplastron contains the anterior bridge strut. The posterior half is made up of two hypoplastra (containing the posterior bridge strut) and the rear is a pair of xiphiplastra. Overlying the boney elements are a series of scutes, which are made of keratin and are a lot like horn or nail tissue. In the center of the carapace are five vertebral scutes and out from these are four pairs of costal scutes. Around

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2856-483: The front, followed by a pair of pectorals, then abdominals, femorals and lastly anals. A particular variation is the Pleurodiran turtles have an intergular scute between the gulars at the front, giving them a total of 13 plastral scutes. Compared to the 12 in all Cryptodiran turtles. The carapace is the dorsal (back), convex part of the shell structure of a turtle , consisting of the animal's ossified ribs fused with

2924-539: The function of mediating the ribs and carapace development later. The PAX1 and Sonic hedgehog gene ( Shh ) serve as key regulators during the development of the vertebral column. Shh expression in the neural tube is essential for the maintenance of Pax1 expression in the ventral sclerotome and thus plays a key role in carapacial rib development. Genetic observations of Pax1 and Shh further provide an understanding in key gene expression that could potentially be responsible for changing turtle morphology. During

2992-464: The name was coined by fishermen who witnessed the turtles dying after being "turned turtle" (on their backs). The fishermen said the turtles "died of a broken heart". Kemp's ridley is the smallest of all sea turtle species, reaching maturity at 58–70 cm (23–28 in) carapace length and weighing only 36–45 kg (79–99 lb). Typical of sea turtles, it has a dorsoventrally depressed body with specially adapted flipper-like front limbs and

3060-570: The northern Atlantic Ocean and Mediterranean Sea, where the Gulf Stream is believed to play a significant role in their dispersal. Confirmed records from Newfoundland to Venezuela in the west; to Ireland , the Netherlands , Malta in the Mediterranean, and numerous localities in between are known in the east, although more than 95% of these involve juveniles or subadults. Several reports from

3128-598: The numbers of Kemp's ridley sea turtles, but today, major threats include habitat loss, pollution , and entanglement in shrimping nets. Some major current conservation efforts are aimed towards habitat protection, reduction of bycatch, rescue and rehabilitation, and reduction of killing. Efforts to protect L. kempii began in 1966, when Mexico's Instituto Nacional de Investigaciones Biologico-Pesqueras (National Institute of Biological-Fisheries Research) sent biologists Hunberto Chávez, Martin Contreras, and Eduardo Hernondez to

3196-463: The olive ridley sea turtles' numbers gradually increase. Kemp%27s ridley Kemp's ridley sea turtle ( Lepidochelys kempii ) , also called commonly the Atlantic ridley sea turtle , Kemp's ridley turtle , and Kemp's ridley , is a species of turtle in the family Cheloniidae . L. kempii is the rarest species of sea turtle and is the world's most endangered species of sea turtle. It

3264-430: The plastron evolved were once floating ventral ribs. During turtle evolution, there was probably a division of labor between the ribs, which specialized to stabilize the trunk, and the abdominal muscles, which specialized for respiration, and these changes took place 50 million years before the shell was fully ossified. The discovery of an ancestral turtle fossil, Pappochelys rosinae, provides additional clues as to how

3332-411: The plastron formed. Pappochelys serves as an intermediate form between two early stem-turtles, E. africanus and Odontochelys, the latter of which possesses a fully formed plastron. In place of a modern plastron, Pappochelys has paired gastralia, like those found in E. africanus . Pappochelys is different from its ancestor because the gastralia show signs of having once been fused, as indicated by

3400-409: The plastron is concave , male or convex , female. This is because of the mating position; the male's concave plastron allows it to more easily mount the female during copulation. The plastral scutes join along a central seam down the middle of the plastron. The relative lengths of the seam segments can be used to help identify a species of turtle . There are six laterally symmetric pairs of scutes on

3468-484: The plastron, though there are exceptions. Moustakas-Verho and Cherepanov's embryological study reveals that the patterning of the plastral scutes appear independent from the patterning of carapacial scutes, suggesting that the carapace and plastron evolved separately. The appearance of scutes correlates to the transition from aquatic to terrestrial mode of life in tetrapods during the Carboniferous period (340 Ma). In

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3536-406: The plastron. This phenomenon occurs in turtle development, but instead of experiencing complete loss of the sternum the turtle body plan repurposes the bone into the form of the plastron, although other analyses find that the endochondral sternum is absent and replaced by the exoskeletal plastron. The ventral ribs are effectively not present, replaced by the plastron, unless the gastralia from which

3604-446: The plastron: gular, humeral, pectoral, abdominal, femoral, and anal (going from the head to the tail down the seam); the abdominal and gular scute seams are approximately the same length, and the femoral and pectoral seams are approximately the same length. The gular scute or gular projection on a turtle is the most anterior part of the plastron, the underside of the shell. Some tortoises have paired gular scutes , while others have

3672-592: The posterior coracoid and their large and wide terminal phalanges creating shovel-like "hands". Fossoriality may have helped Eunotosaurus survive the global mass extinction at the end of the Permian period, and could have played an essential role in the early evolution of shelled turtles. A stem-turtle from the Middle Triassic of Germany, some 240 million years ago, Pappochelys , has more distinctly broadened ribs, T-shaped in cross-section. They vary in shape along

3740-426: The posterior of the shell is the pygal bone and in front of this nested behind the eighth pleurals is the suprapygal. Between each of the pleurals are a series of neural bones, which although always present are not always visible, in many species of Pleurodire they are submerged below the pleurals. Beneath the neural bone is the neural arch which forms the upper half of the encasement for the spinal cord. Below this

3808-602: The relatively shallow waters of the continental shelf (up to 409 m deep, but typically 50 m or less), with females ranging from the southern coast of the Florida Peninsula to the northern coast of the Yucatán Peninsula , while males have a tendency to remain closer to the nesting beaches in the Western Gulf waters of Texas (USA), Tamaulipas , and Veracruz (Mexico). Adults of L. kempii are rarely found outside of

3876-413: The rest of the vertebral column. Some species of turtles have some extra bones called mesoplastra, which are located between the carapace and plastron in the bridge area. They are present in most Pelomedusid turtles. The skeletal elements of the plastron are also largely in pairs. Anteriorly there are two epiplastra, with the hyoplastra behind them. These enclose the singular entoplastron. These make up

3944-438: The scutes mentioned prior or the ribs found internally of the shell. Many ribs can be found within the shell and throughout the shell. The rib structures provide extra structural support but allows the shells to deform elastically depending on the situation the turtle is in (i.e., predatory escape). Nonstructural mechanisms have also been in the turtle shell that aids the turtle during locomotion . A mucus film covers parts of

4012-415: The shell is relatively uniform in structure, species variation in general shape and color being the main differences. However, the soft shell turtles, pig-nose turtles and the leatherback sea turtle have lost the scutes and reduced the ossification of the shell. This leaves the shell covered only by skin . These are all highly aquatic forms. The evolution of the turtle's shell is unique because of how

4080-417: The shell, allowing some physical protection and also reducing friction and drag . The bones of the shell are named for standard vertebrate elements. As such the carapace is made up of eight pleurals on each side, these are a combination of the ribs and fused dermal bone. Outside of this at the anterior of the shell is the single nuchal bone, a series of twelve paired periphals then extend along each side. At

4148-480: The spine. A Late Triassic stem-turtle from Guizhou , China, Eorhynchochelys , is a much larger animal, up to 1.8 metres (5.9 ft) long, with a long tail, and broadened but not overlapping ribs; like the earlier fossils, it has small teeth. Also in the Late Triassic, some 220 million years ago, the freshwater Odontochelys semitestacea of Guangling in southwest China has a partial shell, consisting of

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4216-453: The surface on the squamosal bone where the jaw opening muscles originate, faces to the side rather than to the back. They are the only sea turtles that nest during the day. The distribution of L. kempii is somewhat unusual compared to most reptiles, varying significantly among adults and juveniles, as well as males and females. Adults primarily live in the Gulf of Mexico , where they forage in

4284-476: The sutures into which they insert, known as the Bridge carapace suture. In the shell there is a turtle 's epidermis layer. This layer is important to the strength of the shell surrounding it. In an international study, the layer can be as thick as two to four cells. Even with such a small thickness, the epidermis allows the deformation the shell can experience and provides the shell more support. The epidermis layer

4352-436: The top or bottom of the device. These mechanisms designs are controlled through federal regulations to ensure proper use. There are multiple types of TED construction: oval grid, hooped, fixed angle, Super Shooter, Anthony Weedless, and flounder types. Each design is adapted to be best suited for certain conditions/uses or vary by complexity of the design. In September 2007, Corpus Christi, Texas , wildlife officials found

4420-405: The transitional fossil, Eunotosaurus africanus shows that early ancestors of turtles lost that intercostal muscle usually found between the ribs. The plastron (plural: plastrons or plastra) is the nearly flat part of the shell structure of a turtle , what one would call the belly or ventral surface of the shell. It also includes within its structure the anterior and posterior bridge struts and

4488-410: The turtle shell. It causes axial arrest which causes the ribs to be dorsalized, the shoulder girdle to be rearranged and encapsulated in the rib cage, and the carapace to develop. Odontochelys semitestacea presents evidence of axial arrest that is observed in embryos but lacks fan-shaped ribs and a carapace. This suggests that the primitive carapacial ridge functioned differently and must have gained

4556-424: The turtle stem and on to more crown-ward turtles". Tyler Lyson and colleagues suggest that Eunotosaurus might imply a fossorial origin for the turtles. During the Permian, the broadened ribs may have provided great stability in burrowing, giving a body shape resembling the extant fossorial gopher tortoise , with strong shoulders and forelimbs, and increased muscle attachment structures such as their tubercle on

4624-552: Was developed in 1984, and revised in 1992. A draft public review draft of the second revision was published by National Marine Fisheries Service in March 2010. This revision includes an updated threat assessment . From 1947 to 1985, L. kempii nests experienced a sharp decline from an estimated 121,517 nests in 1947 to 702 nests in 1985 (decline of 99.4%), and have since been exponentially recovering until approximately 2011–2016, where another decline in nests occurred. Nesting as of 2016

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