Ant with mite on its head, in amber.
Photo: Jason Dunlop/Museum für Naturkunde, Berlin
You don't have to go scrabbling around in gravel beds, old quarries or Jurassic Coast beaches like Lyme Regis to find fossils. You can find them in old museums or they can simply arrive in the post as this one did. It was sent to Jason Dunlop, an arachnologist at the Leibniz Institute for Evolution and Biodiversity Science in Berlin, Germany, by a serious collector of fossil spiders who buys quantities of amber and searches through them.
This Baltic Amber is 44-49 million years old (fairly young by geological standards) and contains a rare example of of a fossilised mite and the first of this particular species (Myrmozercon sp.). Significantly, this is also the earliest example of a mite being found attached to its host, in this case the ant Ctenobethylus goepperti, a social insect and member of the Hymenoptera order which includes wasps and bees.
Fossil mesostigmatid mites (Acari: Parasitiformes: Mesostigmata) are extremely rare, and specimens from only nine families, including four named species, have been described so far. A new record of Myrmozercon sp. described here from Eocene (ca 44–49 Myr) Baltic amber represents the first—and so far only—fossil example of the derived, extant family Laelapidae. Significantly, modern species of this genus are habitually myrmecophilous and the fossil mite described here is preserved attached to the head of the dolichoderine ant Ctenobethylus goepperti (Mayr, 1868). It thus offers the oldest unequivocal evidence for an ecological association between mesostigmatid mites and social insects in the order Hymenoptera.
An ant-associated mesostigmatid mite in Baltic amber
Dunlop, J. A., Kontschán, J., Walter, D. E. & Perrichot, V. Biol. Lett. 10, 20140531 (2014).
|Collecting pine resin for Retsina|
Analysis of Baltic amber shows that it most likely came from a species of now-extinct pine, the closest relative of which is the Japanese umbrella pine, Sciadopitys verticillata. Some estimates put the total weight of amber produced by this pine in the Baltic area of Northern Europe at about 105 tons. It is the richest source of fossils of extinct Eocene insects and other arthropods.
The significance of this particular find is that it is the earliest known example of the association between this group of parasitic mites and the Hymenoptera and this group includes the Varroa genus of mite which is believed to be responsible for sudden collapses in honeybee populations and is thus an ecologically and economically important pest. Understanding a bit more of the biology and evolution of this mite could help to find a control measure.
I would love to hear how creationists accommodate the existence of amber with its rich source of fossilised insects and the fact that it too came from an extinct species of pine. What could a putative intelligent designer have been thinking of when it designed these insect traps? Was it just providing us with fascinating pieces of semi-precious jewelry or simply trying to make us think Earth is very old and had a very well diversified biota, including highly specialised parasites, 44-49 million years ago which it intended to kill off before we could see them alive for ourselves?
Answers below, please, if there are any.
'via Blog this'