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本帖最后由 细胞海洋 于 2013-4-15 08:15 编辑 & C6 m% [! |. P: z0 p6 _
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7 Q: [& i2 S& hAbout the cover' b! `6 c: q% w1 x! J
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Fossil dinosaur
8 M8 x @/ ~- A- O9 fembryos are extremely rare, and mainly restricted to the Late Cretaceous period.
0 E% @" N! }( y7 Q: Q a4 ?Hence the interest in a newly uncovered bone bed of Lower Jurassic sauropodomorph % P' J3 j& g0 q4 h1 y7 C$ G* ?
embryos from China, which at about 190–197 million years old is the oldest - h3 q t- O5 E; o7 \
assemblage of such bones ever found. A three-year multinational programme of : ~" M8 u) z5 F4 I7 L5 k4 x( W
excavation and research has yielded a treasure trove of embryonic bones, and the
! A7 J Y' Q& Z7 p# J& holdest known evidence of organic remains. Study of bones preserved at various
+ P+ k2 j4 {9 |. X, e9 Hdevelopmental stages indicates that these large dinosaurs had a short incubation
7 O7 T7 l, l. q( G' K) ntime and flexed their muscles while still in the egg, preparing the growing * W; ]6 b( q+ C' _0 ^
skeleton for life in the outside world. On the cover, a coloured thin section of + c6 E5 V* x* W2 g: }3 Q
an embryonic femur showing its internal tissues and large marrow cavity.
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! I! m* e( I" e G[hide][/hide]
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发表于 2013-4-11 18:36
发表于 2013-4-11 20:09
