Note to moderator: Read answerline carefully.Michael S Y. Lee hypothesized that this structure evolved from a Paraeisaur precursor dubbed the “Polka Dot Ancestor.” Examination of “stem” relatives like Odontochelys and Proganochelys reveals that the axial arrest that occurs during this structure’s formation is linked to an embryonic CR ridge. Citrobacter freundii causes most SCUD-related ulcerations of this structure, which can develop uneven pyramid deformities in malnourished animals. The loss of intercostal muscles contributed to the evolution of this structure which in (*) Pleurodires, unlike most Cryptodires, possesses an extra “intergular” feature on its plastron. The scapula is located inside this structure’s broadened ribs which, like the spine, are ossified to dermal plates to form the carapace. Hinges on these structures allow a certain “box” species to retract their heads. For 10 points, horny scutes cover what structures used for protection by turtles? ■END■
ANSWER: turtle shell [or tortoise shell or Testudine shell; accept shell alone after “turtles” is read; accept turtle carapace or tortoise carapace or Testudine carapace until “carapace” is read; accept turtle plastron or tortoise plastron or Testudine plastron until “plastron” is read; prompt on shell or carapace or plastron by asking “of what animal?”; prompt on rib cage until “ribs” is read] (Modern evidence has refuted the idea that turtles evolved from Paraeisaurs; CR stands for Carapacial Ridge; the intergular feature is the intergular scute.)
<KT, Biology>
= Average correct buzz position