Ontogenetic growth pattern of the extinct megatooth shark Otodus megalodon —implications for its reproductive biology, development, and life expectancy
Ontogenetic growth pattern of the extinct megatooth shark Otodus megalodon —implications for its reproductive biology, development, and life expectancy
复制标题
已灭绝的巨齿鲨（Otodus megalodon）的个体发育生长模式——对其生殖生物学、发育和预期寿命的影响
DOI：
10.1080/08912963.2020.1861608
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发表时间：
2021
影响因子：
1.4
通讯作者：
Griffiths, Michael L.
中科院分区：
文献类型：
--
作者：
Shimada, Kenshu;Bonnan, Matthew F.;Becker, Martin A.;Griffiths, Michael L.
已灭绝的巨齿鲨，Otodus megalodon（Lamniformes：Otodontidae），主要是在晚第三纪海洋化石记录中发现的巨大牙齿。据了解，它的长度至少达到14.1至15.3米，但其生殖生物学和个体发育生长模式在很大程度上仍然处于推测的领域。在这里，我们研究了一个9.2米长的individualO化石椎骨的增量生长带。巨齿鲨，揭示了鲨鱼出生时很大，身长2米，46岁死亡。这种出生时的巨大体型是板状鲨的特征，并表明沿着胚胎的宫内同类相食行为（以食卵的形式）的活产生殖。所生成的生长曲线的轨迹超出死亡年龄和最大长度（约15米）校准从最大的已知牙齿ofO.巨齿鲨的研究表明，该物种的寿命至少为88-100年，至少在前46年的平均增长率约为16厘米/年。作为地球上有史以来最大的食肉动物之一，破译这样的生长参数。巨齿鲨对于理解大型食肉动物在海洋生态系统进化中的作用至关重要。
The extinct megatooth shark,Otodus megalodon(Lamniformes: Otodontidae), is known primarily from its gigantic teeth in the late Neogene marine fossil record. It is known to reach at least 14.1‒15.3 m in length, but its reproductive biology and ontogenetic growth pattern have remained largely in the realm of speculation. Here, we examined incremental growth bands in fossil vertebrae of a 9.2-m-long individualO. megalodon, revealing that the shark was born large, 2 m in length, and died at age 46. This large size at birth is characteristic of lamniform sharks and is indicative of live-bearing reproduction along with embryos’ intrauterine cannibalism behaviour in the form of oophagy. The trajectory of the generated growth curve beyond the age of death and the maximum length (about 15 m) calibrated from the largest known teeth ofO. megalodonsuggest that the species had a lifespan of at least 88–100 years with an average growth rate of about 16 cm/yr at least for the first 46 years. As one of the largest carnivores that ever existed on Earth, deciphering such growth parameters ofO. megalodonis critical to understand the role large carnivores play in the context of the evolution of marine ecosystems.