Parker Joseph, Grimaldi David A
Department of Genetics and Development, Columbia University, New York, NY 10032, USA; Division of Invertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA.
Division of Invertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA.
Curr Biol. 2014 Oct 20;24(20):2428-34. doi: 10.1016/j.cub.2014.08.068. Epub 2014 Oct 2.
Myrmecophiles--species that depend on ant societies--include some of the most morphologically and behaviorally specialized animals known. Remarkable adaptive characters enable these creatures to bypass fortress-like security, integrate into colony life, and exploit abundant resources and protection inside ant nests. Such innovations must result from intimate coevolution with hosts, but a scarcity of definitive fossil myrmecophiles obscures when and how this lifestyle arose. Here, we report the earliest known morphologically specialized and apparently obligate myrmecophile, in Early Eocene (∼ 52 million years old) Cambay amber from India. Protoclaviger trichodens gen. et sp. nov. is a stem-group member of Clavigeritae, a speciose supertribe of pselaphine rove beetles (Coleoptera: Staphylinidae) heavily modified for myrmecophily via reduced mouthparts for trophallaxis with worker ants, brush-like trichomes that exude appeasement compounds, and fusions of many body and antennal segments. Protoclaviger captures a transitional stage in the evolutionary development of this novel body plan, most evident in its still-distinct abdominal tergites. The Cambay paleobiota marks one of the first occurrences in the fossil record of a significant presence of modern ants. Protoclaviger reveals that sophisticated social parasites were nest intruders throughout, and probably before, the ascent of ants to ecological dominance, with ancient groups such as Clavigeritae primed to radiate as their hosts became increasingly ubiquitous.
蚁客（即依赖蚁群社会的物种）包括一些已知在形态和行为上最为特化的动物。显著的适应性特征使这些生物能够突破如堡垒般的安保措施，融入蚁群生活，并利用蚁巢内丰富的资源和保护。这种创新必定源于与宿主的紧密协同进化，但确凿的化石蚁客稀缺，使得这种生活方式的起源时间和方式变得模糊不清。在此，我们报道了来自印度早始新世（约5200万年前）坎贝琥珀中已知最早的形态特化且显然专性的蚁客。新属新种原棒鞭甲（Protoclaviger trichodens）是棒鞭甲科的干群成员，棒鞭甲科是隐翅虫科（鞘翅目：隐翅虫科）中一个种类繁多的超级族，通过减少用于与工蚁交哺的口器、分泌安抚化合物的刷状毛以及许多体节和触角节的融合，为蚁客习性进行了大量形态改造。原棒鞭甲捕捉到了这种新颖身体结构进化发展的一个过渡阶段，这在其仍然明显分开的腹部背板上最为明显。坎贝古生物群是化石记录中现代蚂蚁大量出现的首批事件之一。原棒鞭甲表明，复杂的社会寄生虫在蚂蚁登上生态优势地位的整个过程中，甚至可能在此之前，都是巢穴入侵者，随着它们的宿主变得越来越普遍，像棒鞭甲科这样的古老类群也准备好进行辐射演化。
