Fossil Insects and PlantsFossil insects and associated plants from the Late Triassic Molteno Formation of South Africa
By Dr. John M. Anderson
Photographs: Lambert Smith
One of the most exciting quests in palaeontology must be locating the richest biodiversity hotspot around our planet through geological time!
Left: A sinuous fern frond fossilized together with a cycad leaf, creates a kaleidoscope of form and colour. (Found at Hlatimbe.)
Right: This fossilized wing of a mayfly that lived in the Karoo Basin some 225 million years ago has been beautifully preserved with its venation depicted in amazing detail. (Found at Birds River)
The Late Triassic at around 225 million years ago in Southern Africa turns out to be a strong contender for top podium position as regards terrestrial life. And the Molteno Formation at the heart of the Karoo Basin in South Africa is the clearest window we have onto this hotspot.
It was in the Triassic explosion of new life after the cataclysmic end-Permian global extinction that both the dinosaurs and the mammals (eventually leading to ourselves) originated. It was also in this explosion that the familiar spectrum of today's insect orders appeared, and that the beetles first reached such extraordinary relative diversity. The Molteno Formation, sampled now from 100 localities, represents the crest of this radiation of richness.
Left: A finely detailed impression of a fragment of a fertile osmundaceous fern preserved in chertified mudstone from Konings Kroon.
Right: Another fragment of a different species of fertile osmundaceous fern.
Left: The holotype of a new species of fertile fern from Birds River. The red arrows indicate where marginal feeding by insects has taken place.
Left: Many specimens are so well preserved that under magnification the minute sporangia on the surface of the pinnules of the fertile ferns can be clearly seen.
To give some sense of this compelling moment in Earth time, we aim to place on the current site a growing gallery of images of the fossil insects and the plants amongst which they flourished and evolved. Since a monograph on the fossil ferns of the Molteno is presently in preparation, we begin with this group: here is a first set of fronds and sporangia from several species. As most types are new to science and since the international rules of nomenclature (naming) are such that their names may not be used until officially published, the specimens remain anonymous for the present.
Dr. John M Anderson, Founder & Managing Editor "Gondwana Alive"
Specialist Scientist
South African National Biodiversity Institute, Pretoria
© COPYRIGHT Lambert Smith, 2009
