305 million-year-old baby insects revealed by RCaH researchers

An RCaH / University of Manchester research team has used X-ray techniques to describe two 305 million-year-old juvenile insects. 

The earliest widespread fossils of land animals date from a time period called the Carboniferous, which spanned from 360 – 299 million years ago. During this time period what could be described as the first true rain-forest ecosystems played home to a variety of early land vertebrates, and a wide variety of creepy crawlies. These were often preserved when iron carbonate grew around recently deceased organisms, preserving them in three dimensions. Such fossils, however, are problematic using the traditional approaches of palaeontology – if researchers split open the rock, they are left with a two-dimensional transect of a 3D fossil. Details like limbs can remain buried within the rock.

RCaH researchers Russell Garwood and Professor Philip Withers (also of the School of Materials, Manchester) have used micro-CT – a high resolution form of CT scanning – to describe two juvenile insects from this time period. The reconstructions have revealed an ancestor of the cockroaches  which had long antennae, and generalist mouthparts that suggest the insect could have eaten rotting leaf litter on these early forest floors. The other juvenile is more mysterious. A new genus and species, it quite unlike any insect alive today and was heavily spined – probably a defensive adaptation to make it a less palatable to early ‘amphibian’ predators. 

Insects are actually a very important animal group – they comprise more than 75% of all described living organisms including bacteria, animals, fungi and plants. Despite this, our knowledge of their evolutionary relationships and early evolution is patchy. Studies such as this, applying physical sciences techniques to topics in the life sciences, can help fill in the missing details. Russell Garwood said “This is very much a first step: we’ll be spending the next few years looking at other fossil insects to build on this work. We hope that using an interdisciplinary approach will allow us to better understand the (palaeo)biology, and evolutionary relationships of early insects, and tell us more about early land ecosystems as a whole.” 

The University Of Manchester School of Materials has a team of 15 researchers at RCaH lef by Professors Peter Lee and Philip Withers. Part of the Manchester X-ray imaging facility, this group applies X-ray techniques to a range of research problems across the life and materials sciences.