The Caytoniales is an extinct order of seed plants

Spermatophyte

The spermatophytes comprise those plants that produce seeds. They are a subset of the embryophytes or land plants...

 whose presence is recorded in fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s collected throughout the Mesozoic Era (around ). The plants are part of the group called seed ferns because they are seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

-bearing plants with fern

Fern

A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...

-like leaves.

The first fossils to be identified in this order were discovered in a Middle Jurassic

Middle Jurassic

The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....

 formation in Yorkshire

Yorkshire

Yorkshire is a historic county of northern England and the largest in the United Kingdom. Because of its great size in comparison to other English counties, functions have been increasingly undertaken over time by its subdivisions, which have also been subject to periodic reform...

. The plants are believed to have grown in wetland

Wetland

A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....

s of some nature and may have been small tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s. They are considered a gymnosperm

Gymnosperm

The gymnosperms are a group of seed-bearing plants that includes conifers, cycads, Ginkgo, and Gnetales. The term "gymnosperm" comes from the Greek word gymnospermos , meaning "naked seeds", after the unenclosed condition of their seeds...

 by many botanical authorities, but were once thought to have an evolutionary relationship with the angiosperms, or flowering plants, because their seeds are born in a partially enclosed cupule (a modified leaf

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 with reproductive

Plant sexuality

Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....

 organs). The leaves are palmately compound with 3-6 leaflets 2-6cm in length. The pollen grains are winged, like those of gymnosperms, and the pollen is bisaccate like the pollen of pine trees.

Form taxa

• Sagenopteris -- leaves
• Caytonanthus -- microsporophyll
  Sporangium
  A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
  
  , or pollen producing organ
• Caytonia -- ovule