Harvesting the extinct Bennettitales

Stephen McLoughlin and Christian Pott (Sweden) Just as the animal kingdom lost some remarkable designs during the mass extinction events that punctuated the Palaeozoic and Mesozoic (consider the disappearance of the novel carapaces of trilobites and the aerofoils of pterosaurs), so too the plant kingdom lost some majestic groups that, had they survived until today, would no doubt have been cultivated as centrepieces in many domestic gardens. One such group is the Bennettitales. The Bennettitales were enigmatic, seed-bearing plants (gymnosperms) characterised by complex reproductive structures, some of which are not yet fully understood. Bennettitales are historically divided into two families, the Cycadeoidaceae (or Bennettitaceae) and the Williamsoniaceae. The two families are distinguished primarily by their growth habit and the arrangement of their reproductive organs. The former have short, stocky trunks somewhat like modern cycads, whereas the latter had slender, profusely branched stems. The former appear to have been restricted to the Jurassic-Cretaceous of western Laurasia, whereas the latter had a global distribution and greater temporal range. They were neither the smallest plants of the Mesozoic nor the largest. They were one of the important, mid-storey elements of the vegetation. If you care to view almost any artist’s reconstruction of a Jurassic landscape you will no doubt see bennettitaleans growing around the feet of (or being eaten by) a large sauropod or ornithischian dinosaur. Fig. 1.. A 45cm-tall permineralized cycadeoidaceae stem (Cycadeoidea dacotensis) from the Cretaceous of northern USA. Flowers before there were flowers Apart from their growth habit, the most … Read More