Frenelopsis is a genus of extinct conifers belonging to the family Cheirolepidiaceae that lived throughout the Cretaceous period ranging from the Berriasian to the Maastrichtian stages,[1][2] containing a total of 18 species.
[2] It is a form classification describing the shoots of the plant, and is accompanied by the genera Classopollis, Classostrobus, and Alvinia.
[2] The shoots of Frenelopsis consist of a round, jointed stem with small, sheathing leaves at the nodes.
[1] It is speculated that the growth form of the entire plant ranged from being a shrub to trees growing up to 20 meters in height[2] The Classostrobus cones of Frenelopsis often are found near the shoots.
[2] The large Alvinia cones associated with Frenelopsis consist of helically arranged scales.
These scales in turn consist of a covering flap and three appendages that together form a funnel-like structure.
The cones' flattened shape in fossils provides evidence that they consist of soft tissues and are herbaceous in nature.
[1][2] The high ecological plasticity of Frenelopsis likely allowed them to compete with angiosperm plants, which outcompeted many other non-flowering clades.
[2] Frenelopsis initially had a wide range between the Berriasian and Hauterivian stages of the Cretaceous spanning from the Tethyan Archipelago in Europe to eastern Asia.
Between the Barremian and the Aptian stages, the genus underwent a specific radiation across the Tethyan Archipelago while disappearing from Africa.
F. ramosissima still persisted through this time, while F. harrisii appeared in what is now Tajikistan while F. choschiensis has long since gone extinct.
Finally, towards the end of the Cretaceous period in the Campanian and Maastrichtian stages, only F. oligostomata of Frenelopsis remained on the Iberoamorican domain, a large island consisting of what is now the Iberian Peninsula and western France.
While the species was the last, it still dominated the areas it grew in, existing in large numbers in what would become Portugal and the Pyrenees.