''Credneria'' is an extinct
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
in the family or
Platanaceae
Platanaceae, the plane family, is a family (biology), family of flowering plants in the order Proteales. The family consists of only a single extant taxon, extant genus ''Platanus'', with twelve known species. The plants are tall trees, native ...
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. The type ...
'' species that appeared during the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
. The genus was first described by
Zenker (
1833
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* February 6 (January 25 on the Greek calendar) – Prince Otto Friedrich Ludwig of Bavaria arr ...
) and has formerly been placed in the family
Salicaceae
The Salicaceae are the willow family of flowering plants. The traditional family (Salicaceae ''sensu stricto'') includes the willows, poplars. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly expanded the circumsc ...
rather than Platanaceae on occasion. ''Credneria'' leaves are preserved in sandstone and less often in siltstone. The leaves are typically
obovate
The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...
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 or leafing is the formation of new leaves or fronds. In plant anatomy, it ...
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),junior synonym
In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently.
...
s of the platanaceous species '' Pseudoprotophyllum boreale''.Cenomanian
The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...
Melozi and Kaltag formation
Kaltag (; ; ) is a city
and village in Yukon-Koyukuk Census Area, Alaska, United States. At the 2010 census the population was 190, down from 230 in 2000.
History
Kaltag was a Koyokon Athabascan area used as a cemetery for surrounding ...
s along the Yukon River
The Yukon River is a major watercourse of northwestern North America. From its source in British Columbia, it flows through Canada's territory of Yukon (itself named after the river). The lower half of the river continues westward through the U.S ...
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