At the time of this event in the Early Cretaceous Period, huge animals such as dinosaurs still dominated the Earth, but scurrying beneath them were early mammals and large numbers of terrestrial invertebrates, such as these insects. Soldier beetles, then as now, were omnivores that lived on things like aphids, other tiny insects or plant pollen. Among other things, this finding pushes back the known existence of this type of beetle by about 60 million years. And at that distant time, they had already evolved ways to defend themselves.
This beetle was able to exude a sticky chemical substance that was irritating to potential predators, and caused them to go away or leave it alone, Poinar said. It could even conserve its excretions and control the direction of the defense; in other words, produce the substance only on its left rear side if that was where the attack was coming from.
Building on these types of early defense mechanisms, Poinar said, modern insects now have a wide range of defensive chemical arsenals things that are distasteful, nauseating or caustic, from chemicals such as phenols, aldehydes and ketones. Some contemporary soldier beetles can produce types of carboxylic acid, as well as triglycerides and glyceride esters.
In insects, these types of defensive mechanisms are often a key to their survival.
Amber provides a unique mechanism to preserve specimens such as this. Beginning as viscous sap from certain kinds of trees, it can trap small animals or other materials, acts as a natural embalming agent, and eventually can turn into a semi-precious stone that displays these ancient life forms in nearly perfect, three-dimensional form. The phenomena has been invaluable in scientific and other ecological research, allowing experts to help re-create more accurate pictures of ancient ecosystems
|Contact: George Poinar|
Oregon State University