A sea turtle's salty tale.The evolutionary origin of sea turtles has been a tough shell for paleontologists to crack, but a fossil discovery in Brazil has penetrated some of their hidden history. The exceptionally well preserved specimen, found in 110-million-year-old rocks, pushes back the record of marine turtles by 10 million years. Measuring 20 centimeters in length, the specimen has relatively primitive paddles, with moveable fingers and toes Fingers and Toes See also anatomy; body, human; hands. adactyly a birth defect in which one or more fingers or toes are missing. dactyl a digit; a finger or toe. See also measurement. that resemble those in freshwater turtles. The limbs in this species, Santanachelys gaffneyi, had not yet evolved into the rigid flippers n. 1. A type of shoe with a paddle-like front extending well beyond the end of the toe, used an aid in swimming (especially underwater). seen in modern marine turtles. Other adaptations to sea life had developed in this early species, however. S gaffneyi had enlarged eye sockets, indicating that huge lachrymal lach·ry·mal also lac·ri·mal adj. 1. Of or relating to tears. 2. Of, relating to, or constituting the glands that produce tears. salt glands surrounded their eyes, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. Ren Hirayama of Teikyo, Heisei University in Ichihara, Japan. The lachrymal glands are important for removing salt from the animal's body. The fossil reveals that, in their invasion of the sea, these forerunners of marine turtles developed the capacity to deal with excess salt before evolving an efficient propulsion system Noun 1. propulsion system - a system that provides a propelling or driving force system - instrumentality that combines interrelated interacting artifacts designed to work as a coherent entity; "he bought a new stereo system"; "the system consists of a motor and a , Hirayama reports in the April 16 Nature. |
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