Marine Turtle Evolution, Phylogeny, Classification, and Current Status Flashcards
What period did the earliest turtle fossils appear?
80 million years after reptiles started evolving (Triassic period)
What is Proganochelys?
a fossil turtle resembling a modern snapping turtle, considered one of the earliest turtle fossils.
How long ago did modern sea turtles evolve?
120 million years ago (Cretaceous period)
What are the four families of sea turtles that survived the extinction event at the end of the Mesozoic Era?
Toxochelyidae, Protostegidae, Cheloniidae, Dermochelyidae.
What is the common name of Chelonia mydas?
green sea turtle.
How many species of sea turtles are currently recognized?
Scientists recognize eight
What type of habitat do leatherback sea turtles primarily prefer?
open ocean.
What is the average incubation period for loggerhead sea turtle eggs?
60 days.
What is the scientific name of the hawksbill sea turtle?
Eretmochelys imbricata.
What characteristic features define the Dermochelyidae family of sea turtles?
no scutes and a carapace composed of a mosaic of small bone plates.
Describe the diet of green sea turtles.
Green sea turtles are primarily herbivorous as adults and mainly eat seagrass and algae, while juveniles eat various invertebrates.
What is a significant threat to loggerhead sea turtles’ survival?
loss of nesting habitat due to coastal development.
What is the approximate weight range of adult leatherback sea turtles?
550 - 1,545 pounds.
How do sea turtles relate to human disturbances during nesting?
Human disturbances such as coastal lighting and housing developments can cause disorientation in hatchlings emerging from their nests.
Which sea turtle species is known for its narrow head and hawk-like beak?
hawksbill sea turtle
What is unique about the carapace of the leatherback sea turtle?
lacks hard shell; has flexible carapace composed of tough, rubbery skin.
Which sea turtle is considered critically endangered?
The hawksbill sea turtle is listed as critically endangered.
What feature differentiates the olive ridley sea turtle from the other species?
nearly circular shell with six lateral scutes.
What is the common threat faced by the Kemp’s ridley sea turtle?
collection of eggs and incidental capture in fishing gear.
In terms of nesting behavior, what is unique to the Kemp’s ridley sea turtle?
mass synchronized nesting events, known as arribadas.
Which sea turtle species primarily feeds on jellyfish?
The leatherback sea turtle
What does molecular studies tell us about sea turtles?
evolutionary history, reproductive behavior, and ecology
How many nests does a loggerhead sea turtle lay each season?
average of 4 to 7 nests per season.
What adaptation allows the Archelon ischyros to be one of the largest sea turtles?
The Archelon ischyros had a hard shell covered with a bony framework allowing it to grow to lengths of 15 feet.
What do the scutes on a sea turtle’s shell indicate?
The number and arrangement of scutes on a turtle’s shell are used to help determine the species.
How many living families of marine turtles are there?
two: Cheloniidae and Dermochelyidae.
What is a major factor contributing to the decline of green sea turtle populations?
commercial harvesting of eggs and meat
What feature characterizes the loggerhead sea turtle?
exceptionally large head and strong jaws.
In terms of physical characteristics, how does the flatback sea turtle differ from other sea turtles?
rounded, flattened body shape; uniformly flat carapace
Why are eggs of the Kemp’s ridley turtle particularly vulnerable?
Kemp’s ridley turtle eggs are vulnerable due to human activities such as poaching and habitat destruction during nesting.
What aspect of sea turtle anatomy helps them have a streamlined body for swimming?
large flippers and streamlined body shape that aid in adapting to life in the sea.
What is the population estimate for olive ridley nesting females?
800,000.
What is notable about the diet of the Kemp’s ridley sea turtle?
Kemp’s ridley sea turtles have powerful jaws that help them crush and grind their food, which includes crabs and jellyfish.
What genetic analysis method is employed to examine sea turtles?
DNA fingerprinting techniques, such as microsatellite and minisatellite analyses, are used to investigate the genetic diversity of sea turtles.
Describe the relationship between turtles and temperature regulation.
Sea turtles are ectothermic (cold-blooded) and rely on external environments to regulate their body temperature.
How far can leatherback sea turtles migrate?
Leatherback sea turtles can migrate thousands of miles across oceans.
What is a significant evolutionary adaptation of turtles related to their development of shells?
The development of the carapace (upper shell) and plastron (lower shell) provided turtles with significant evolutionary advantages for protection.
What distinguishes the leatherback sea turtle from those in the Cheloniidae family?
lacks scutes and has a softer, leathery body compared to the hard-shelled turtles in the Cheloniidae family.
What are common threats to the survival of all sea turtle species?
habitat loss, climate change, pollution, and entanglement in fishing gear.
What is the significance of DNA studies in understanding turtle populations?
DNA studies enable researchers to determine population structure, gene flow, and identify unique lineages among turtle species.
