Tempskya

Tempskya is an extinct genus of tree-like fern that lived during the Cretaceous period. The genus is known from several petrified specimens from various locations across the Northern Hemisphere.[2] Specimens have also been recovered in Argentina and Australia.[3]

Tempskya
Temporal range: Cretaceous
Tempskya fossil slab and reconstruction on display
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Class: Polypodiopsida
Subclass: Polypodiidae
Order: incertae sedis
Family: †Tempskyaceae
Genus: †Tempskya
Corda (1845)[1]

Description

Specimens of Tempskya could grow to be up to 14.75 feet (4.5 meters) tall.[2] Its trunk was actually a large collection of stems surrounded by adventitious roots.[2] The false trunk could be up to 50 cm in diameter.[4] Thin leaves have been discovered for the first time on T. wyomingense specimens;[1] the more commonly seen fossilized leaf bases show that they covered the upper part of the trunk.[2]

Hypothesized growth pattern

Examination of cross sections of various Tempskya specimens shows that those with the largest trunks have the smallest number of stems, and vice versa.[4] From this, a possible growth pattern of Tempskya has been suggested: at the sporeling stage, Tempskya would consist of a single stem, which would begin to branch off distally. A "mantle" of adventitious roots would then develop around the stems to support them. Later on, many of the stems would begin to decay, while the adventitious roots would still provide support and absorb water for the grown plant.[4] This growth pattern has also been hypothesized for Psaronius.[4]

Taxonomy
Tempskya sp. - Reconstruction at MUSE - Science Museum in Trento

Tempskya was originally described in 1824 as Endogenites erosa before being described as Tempskya by August Carl Joseph Corda in 1845.[1] The four species originally described by Corda were, in order: T. pulchra, T. macrocaula, T. microrrhiza, and T. schimperi.[5]

Tempskya is the sole member of the family Tempskyaceae.[2] The family has been placed in the order "Filicales",[4] which is now split into a number of orders of leptosporangiate ferns.

Fossil sites

Tempskya finds were thought to be exclusive to the Northern Hemisphere until specimens were discovered in Argentina and Australia (in 2003 and 2005, respectively). Tempskya fossils have also been discovered in the Czech Republic (2002) and Japan (1986).[3] Tempskya were frequently found fluvial deposited in gravel pits in Germany. Its origin is not clear, in part they came certainly from Czech sites.

gollark: It is literally the cheapest ryzen.
gollark: `ssh sinthorions-computer.com cat /proc/cpuinfo`
gollark: That's horrible.#
gollark: processor : 0vendor_id : AuthenticAMDcpu family : 23model : 1model name : AMD Ryzen 3 1200 Quad-Core Processorstepping : 1microcode : 0x800111ccpu MHz : 3410.279cache size : 512 KBphysical id : 0siblings : 4core id : 0cpu cores : 4apicid : 0initial apicid : 0fpu : yesfpu_exception : yescpuid level : 13wp : yesflags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb hw_pstate sme ssbd sev vmmcall fsgsbase bmi1 avx2 smep bmi2 rdseed adx smap clflushopt sha_ni xsaveopt xsavec xgetbv1 xsaves clzero irperf xsaveerptr arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif overflow_recov succor smcabugs : sysret_ss_attrs null_seg spectre_v1 spectre_v2 spec_store_bypassbogomips : 6989.20TLB size : 2560 4K pagesclflush size : 64cache_alignment : 64address sizes : 43 bits physical, 48 bits virtualpower management: ts ttp tm hwpstate eff_freq_ro [13] [14]
gollark: Look, it even lists the bugs!

References
  1. Tidwell, William D.; Hebbert, Naomi (September 1992). "Species of the Cretaceous Tree Fern Tempskya from Utah". International Journal of Plant Sciences. 153 (3): 513–528. JSTOR 2995693.
  2. Palmer, Douglas; et al. (2009). Prehistoric life : the definitive visual history of life on earth (1st American ed.). New York: Dorling Kindersley. p. 286. ISBN 978-0-7566-5573-0.
  3. Gee, Carole T. (2010). "Oldest Known Dicotyledonous Lianas From the Early Late Cretaceous of Utah and New Mexico, U.S.A.". Plants in Mesozoic time : morphological innovations, phylogeny, ecosystems (illustrated ed.). Bloomington: Indiana University Press. p. 271. ISBN 0-253-35456-0. Retrieved 25 January 2012.
  4. Taylor, Thomas N.; Taylor, Edith L.; Krings, Michael (2009). "Ferns and Early Fernlike Plants". Paleobotany : the biology and evolution of fossil plants (2nd ed.). Amsterdam: Academic Press. pp. 457–459. ISBN 0-12-373972-1. Retrieved 24 January 2012.
  5. Stephenson, Lloyd William (1936). "American Cretaceous Ferns of the Genus Tempskya". New Upper Cretaceous Ostreidae From the Gulf Region. Washington: United States Government Printing Office. p. 108. Retrieved 25 January 2012.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.