在最早的脊椎动物中,牙和下巴的发育
Martin Rücklin1, Philip C J Donoghue, Zerina Johanson
1School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK. m.ruecklin@bristol.ac.uk
Nature
|October 19, 2012
概括
早期的脊椎动物,皮动物,拥有真正的连续牙,而不是融合的牙状结构. 这一发现澄清了脊椎动物牙和的进化起源.
科学领域:
- 古生物学的古生物学
- 进化发育生物学 进化发育生物学
- 脊椎动物古生物学 脊椎动物古生物学
背景情况:
- 和牙是脊椎动物进化中的关键创新,是适应性辐射的核心.
- 牙的进化起源以及它们在已灭绝的黑皮动物中的存在仍然存在争议.
- 斑皮动物,一个灭绝的姐妹群的chondrichthyans和osteichthyans,拥有下巴,但他们的牙结构是有争议的.
研究的目的:
- 调查已灭绝的平原体Compagopiscis croucheri.牙的存在和性质.
- 为了澄清早期脊椎动物牙和的进化起源.
- 为了确定 placoderm 牙结构是否代表真牙或融合进化.
主要方法:
- 使用同步子辐射X射线断层显微镜 (SRXTM).
- 分析了Compagopiscis croucheri标本的一个发育系列.
- 检查了下巴和牙的发育,结构和组成.
主要成果:
- 斑体下巴包括不同的软骨,骨化和皮肤元素.
- 在Compagopiscis的牙骨化是连续牙的复合结构.
- 这些由牙和骨组成的牙和骨腔,与其他石皮结构不同.
结论:
- 康帕戈皮斯基斯和其他关节动物拥有真牙,而不是融合的牙状结构.
- 连续性牙在牙骨的早期发展,在的起源后不久.
- placoderms 中的牙和部发育没有整合,反映出不同的进化起源.
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