Callistophytales is an extinct order of spermatophytes (seed plants) which lived from the Pennsylvanian (Late Carboniferous) to Permian periods. They were mainly scrambling and lianescent (vine-like) plants found in the wetland "coal swamps" of Euramerica and Cathaysia. Like many other early spermatophytes, they could be described as "seed ferns", combining ovule-based reproduction with pinnate leaves superficially similar to modern ferns.
Callistophytales is an extinct order of spermatophytes (seed plants) which lived from the Pennsylvanian (Late Carboniferous) to Permian periods. They were mainly scrambling and lianescent (vine-like) plants found in the wetland "coal swamps" of Euramerica and Cathaysia. Like many other early spermatophytes, they could be described as "seed ferns", combining ovule-based reproduction with pinnate leaves superficially similar to modern ferns.
Callistophytales in particular are characterized by their reproductive anatomy. The ovules are bilaterally symmetrical and non-cupulate, attaching to the underside of pinnules that were otherwise morphologically identical to the standard non-reproductive pinnules. The pollen-bearing organs are small compound structures formed from up to eight tapering sporangia fused at their base. They are also borne on the underside of unmodified pinnules. Callistophytalean pollen was saccate (bearing buoyant sacs). Callistophytales were reproductively more sophisticated than most other Palaeozoic pteridosperms, some of which they seem to have out-competed and replaced in the "coal swamp" vegetation during Late Pennsylvanian and Permian times.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).