''Credneria'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

in the family or

Platanaceae Platanaceae, the "plane-tree family", is a family of flowering plants in the order Proteales. The family consists of only a single extant genus ''Platanus'', with eight known species. The plants are tall trees, native to temperate and subtropic ...

of broad-leaf trees similar to extinct ''

Platanus ''Platanus'' is a genus consisting of a small number of tree species native to the Northern Hemisphere. They are the sole living members of the family Platanaceae. All mature members of ''Platanus'' are tall, reaching in height. All except f ...

'' species that appeared during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

. The genus was first described by Zenker (

1833 Events January–March * January 3 – Reassertion of British sovereignty over the Falkland Islands (1833), Reassertion of British sovereignty over the Falkland Islands in the South Atlantic. * February 6 – His Royal Highness Prince Otto ...

) and has formerly been placed in the family

Salicaceae The Salicaceae is the willow family of flowering plants. The traditional family (Salicaceae ''sensu stricto'') included the willows, poplar, aspen, and cottonwoods. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly ...

rather than Platanaceae on occasion. ''Credneria'' leaves are preserved in sandstone and less often in siltstone. The leaves are typically

obovate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

with a pinnate-actinodromous

venation Venation may refer to: * Venation (botany), the arrangement of veins in leaves * Wing venation, the arrangement of veins in insect wings See also * * Vernation Vernation (from ''vernal'' meaning ''spring'', since that is when leaves spring forth ...

and distinct suprabasal veins.

Species

Known species are: * *''Credneria biloba'' *''Credneria bohemica'' *''Credneria comparabilis'' *''Credneria cuneifolia'' *''Credneria daturaefolia'' (

Ward Ward may refer to: Division or unit * Hospital ward, a hospital division, floor, or room set aside for a particular class or group of patients, for example the psychiatric ward * Prison ward, a division of a penal institution such as a pris ...

) *''Credneria denticulata'' *?''Credneria grewiopsoides'' *''Credneria integerrima'' *?''Credneria longifolia'' *''Credneria pachyphylla'' *''Credneria parva'' *''Credneria prophylloides'' ( Knowlton) *''Credneria pulchra'' *?''Credneria spatiosa'' *''Credneria subserrata'' (Hampe) *''Credneria subtriloba'' *''Credneria sudanense'' *''Credneria triacuminata'' ( Hampe) The species ''Crednetia basinervosa'' ( Hollick), ''C. elegans'' (Hollick), ''C. inordinata'' (Hollick), ''C. intermedia'' (Hollick), ''C. mixta''(Hollick), and ''C. truncatodenticulata'' (Bell) have all been identified as

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

s of the platanaceous species '' Pseudoprotophyllum boreale''. The species ''Credneria grewiopsoides'' (Hollick), ''C. longifolia'' (Hollick) and ''C. spatiosa'' (Hollick) from the

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

Melozi and Kaltag formations along the

Yukon River The Yukon River (Gwichʼin language, Gwich'in: ''Ųųg Han'' or ''Yuk Han'', Central Alaskan Yup'ik language, Yup'ik: ''Kuigpak'', Inupiaq language, Inupiaq: ''Kuukpak'', Deg Xinag language, Deg Xinag: ''Yeqin'', Hän language, Hän: ''Tth'echù' ...

in Alaska are also possibly representatives of ''Pseudoprotophyllum boreale'', but the known fossil material for the species was considered to incomplete to make a determination.

References

{{Taxonbar, from=Q1139441 Cretaceous plants Platanaceae Salicaceae Fossil record of plants