Description

Buckthorn flower (Rhannacaea)

Early Paleocene (Danian)

Salamanca Formation

Chubut Province Argentina

5mm flower on 55mm slab.  First we have ever seen.  Extremely rare.

Plant.

The buckthorn is a plant in the Family Rhannacaea.  This specimen represents the earliest-known occurrence of the this plant and it comes from a time perhaps as little as one million years after the K/T mass extinction event.

Today, buckthorns live in subtropical and temperate regions, introduced by humans in some cases.  It appears these plants originated in South America and spread to Antarctica and Australia, moving north from there, while world climates were warmer early in the Cenozoic Era.