Drepanophycaceae is a family of extinct

lycophyte The lycophytes, when broadly circumscribed, are a group of vascular plants that include the clubmosses. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineag ...

s of Late

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

to Late

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

age (), found in North America, China, Russia, Europe, and Australia.

Description

The stems are several mm to several cm in diameter and several cm to several metres long, erect or arched, dichotomizing occasionally, furnished with true roots at the base.Hueber 1992, p. 491 (''Baragwanathia'') and 492 (''Drepanophycus'') Vascular bundle an exarch actinostele,

tracheid A tracheid is a long and tapered Lignin, lignified cell in the xylem of Tracheophyta, vascular plants. It is a type of conductive cell called a tracheary element. Angiosperms also use another type of conductive cell, called vessel elements, to t ...

s of primitive annular or helical type (so-called G-type). Leaves are unbranched

microphyll In plant anatomy and evolution a microphyll (or lycophyll) is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of ...

s several mm to 2 cm or more long with a single prominent vascular thread, arranged spirally to randomly on the stem. Homosporous sporangia borne singly on the upper leaf surface or in an axillary position.See tables 2 & 3 in Gensel (1992) for list of these anatomical details. Drepanophycaceae differs from a related family of the same period, Asteroxylaceae, in having vascularized

s; see

Drepanophycales Drepanophycales is an order of extinct lycophyte plants of Late Silurian to Late Devonian age (around ), found in North America, China, Russia, Europe, and Australia. Sometimes known as the Asteroxylales or Baragwanathiales. Description Extinct ...

for more details.

Genera

The genera in the family are: *''

Drepanophycus ''Drepanophycus'' is a genus of extinct plants of the division Lycopodiophyta of Early to Late Devonian age (around ), found in Eastern Canada and Northeast US, China, Russia, Egypt and various parts of Northern Europe and Britain. Description ...

'' Göppert (type genus) **microphylls short, tapering rapidly from wide base (thorn-shaped) **microphylls arranged spirally or randomly on stem **sporangia borne on upper surface of microphylls *''

Baragwanathia ''Baragwanathia'' is a genus of extinct lycopsid plants of Late Silurian to Early Devonian age (), fossils of which have been found in Australia, Canada, China and Czechia. The name derives from William Baragwanath who discovered the first speci ...

'' Lang & Cookson **microphylls long, not tapering over most of length (strap-shaped) **microphylls arranged spirally on stem **sporangia borne axially (whether on microphylls or on stem is not known)

Notes

References

* * {{Taxonbar, from=Q16743624 Devonian plants Silurian plants Drepanophycales Prehistoric plant families Silurian first appearances Late Devonian extinctions Prehistoric lycophytes