''Palissya'' is an extinct

form genus Form classification is the classification of organisms based on their morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncertainty; the goal of s ...

of female (ovule-bearing)

conifer cones A conifer cone (in formal botanical usage: strobilus, plural strobili) is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers an ...

, known from the Late Triassic (

Rhaetian The Rhaetian is the latest age of the Triassic Period (in geochronology) or the uppermost stage of the Triassic System (in chronostratigraphy). It was preceded by the Norian and succeeded by the Hettangian (the lowermost stage or earliest age ...

) to the Early Cretaceous (

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

). The cone of ''Palissya'' is noted for its unusual

catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged cl ...

-like construction: Slender bracts (modified leaves) are rigidly attached in a helical pattern around a tall woody core. The adaxial (upper) surface of each bract bears two parallel rows of

ovules In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the fe ...

which are encased in cup-like structures formed by scales. The seeds are thin-walled and were likely only viable for a short period of time, meaning that they were probably adapted to wind dispersal. ''Palissya'' has been considered in some aspects to be similar to some Paleozoic Voltziales, as well as Taxaceae and Podocarpaceae. Most leaves assigned to the genus do not belong to the same plant as the conifer cone. ''Palissya'' specimens from the Middle Jurassic of Yorkshire are associated with '' Elatocladus-''like leaves. Several

Australasian Australasian is the adjectival form of Australasia, a geographical region including Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continen ...

species with fragile cones were referred to the separate genus '' Knezourocarpon'', though some were later moved back into ''Palissya''. Other related cone genera include '' Stachyotaxus'', '' Metridiostrobus'', and '' Compsostrobus'', all from the Late Triassic of the Northern Hemisphere. True specimens of ''Palissya'' first appeared in the Northern Hemisphere during the latest Triassic (

) and spread to Eastern Gondwana (modern Australia, New Zealand, and Antarctica) during the Middle Jurassic. The youngest known records of ''Palissya'' in the Northern Hemisphere are from the Middle Jurassic, but ''Palissya'' persisted in Eastern Gondwana into the Early Cretaceous, with the youngest records being from the

Species

After

References

{{Taxonbar, from= Q87232513, from2= Q108208266 Fossil record of plants Extinct plants of New Zealand Conifers Prehistoric gymnosperm genera