Evolution and Ecology of the Cathaysia flora Sun Keqin & Shaila Chandra Sun Keqin & Chandra S 1998. Evolution and ecology of the Cathaysia flora. Palaeobot.anist 47 : 20-28. The Cathaysia flora, one of four famous floras of Late Carboniferous and Permian periods in the world, is mainly distributed in Asia, such as China, Korea, Japan, Laos, Thailand, Indonesia, Malaysia, etc. China is one of the most important country for the Cathaysia flora, which derived from the identical Lepidodendropsis flora of the Early Carboniferous on a global scale. From the beginning of the Namurian A, the Cathaysia flora gradually separated from the global Lepidodendropsis flora and it could be recognized as an independent flora in the early Late Carboniferous (Namurian B to C). According to the succession of the Cathaysia flora of different geological ages, the flora may be divided into seven fossil-plant assemblages from early Late Carboniferous to late Late Permian so as to reflect the characteristics of floral evolutionary stages. From the early Late Carboniferous to the early Late Permian, the typical elements of the Cathaysia flora gradually increased. The Cathaysia flora ranged from the beginning of the early Late Carboniferous to the end of the Permian in age. The most obvious changes of dry climate and tectonic movement caused the extinction of the Cathaysia flora by the end of the Late Permian. The Cathaysian floral province, located in the equatorial region under tropical climatic condition during the Carboniferous and Permian, was characterized by lycopods, ferns, pteridosperms, sphenopsids and cordaitean gymnosperms. The vertical structure of floral communities included arbores, tree ferns, shrubs and herbs. Kay- Words - Cathaysia flora, Carboniferous, Permian, Evolution, Palaeoecology. Sun Keqin, China University o/Geosciences, Beijing 100083, China. Shaila Chandra, Bi,.bal Sahni Institute 0/Palaeobotany, 53, University Road, Lucknow 226 007, India. "ffiXi~ ~ ~ ~ ~ ftnn <H fqRl \jj Id q>[ q<:jf ... ,. FI\ ILl ~ <), fcl>'f 10i ~ <R;I ~ ~ ~ ~ ~ ~ ~ 1(CP~. ~ <li~ q'ifGff1\i1lt1 CfiI<n·'''Iq,'fl10i TJ <),<rR q'ifGff1\imri -q vn - ~ ~-qqp:n\ilTffi ~ ~<li~ <),~~~ ~ ~."Cfi'Iftm."VfI"ln"'i. ~3lRl.~. *o:sl:1~IIOlI. I q'ifGff1\i1tt'1 ~ ~"ViR ~~ ~ '0'lFG:sH~d:~ifl' ~ ~"§3lT -q 1(CP~. ~"I:l"t: Cfil<n·-?Jq,'fl TJ -q mMrfi1Cfi"ffi"'( qx <), q'ifGff1\i1It'1 ~ ~ ~ ~wn ~ ~ ~ ~ I TJ <), 31W+l -q "I:l"t: q'i{qff1\i1It'1 1(CP Q'ifGff1\i1It'1 '01 FG:S];g"!?1 [qjfl' iJ 7T<n 3lR \3"m ~ ,~ <li~ CfiI6l1'1~q,Hi TJ (~<fI ~ ~"ffCfi) -q 1(CP ~~ Q'ifGff1\i1It'1 <), "'<"iQ -q ~ .:wRt ffiffi q;"'( c:f\ I q'i,;qff1\i1It'1 mifi1Cfi\mR"CfiTiil~TJ<),~~~TJ<),3R1"ffCfi>ll"'{f-gm'g I Fctfi1;:;'l~-goTI<)'<li~ Q'ifGff1\i1it'11 "Cfil3lUl<r'l~ ~~ ~ ~ ~ ~ qx R \mR CfiI6l1;:f1q"fl TJ mifi1Cfi \mR TJ <), 'lU1 me'! -q FcPrcffi fcl>m 7T<n. ffifc(; q'i,;qff1\i1It1 ~ <li~ ~ ~ ~ \mR"CfiTiil~ ~ ~ <f; fctcm!<),Fctfi1;:;'l3l11ffiar:rfi q;) ~~ <iT! ~ fcl>m"\ifl I \mR TJ"ffCfi ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ q'ifGff1\i11t'11 <), fclftr1'e mm M I TJ <), WW<f N:1 qx -q 3lT"ViR ('1m -q ~ ~ ~ ~~ ~ ~ N:1 \llTl fclftr1'e qftq*fi <), "CfiRUlZl Q'ifGff1\i1It'1 fcl<:r<l iJ I CfiI6l1;:f1q,,'(i -goTI <), e1::I <), ~ ~'iI~t'1<fJRitlOll ~ ~C'lar:rfi"Cfil wil'ilfq1~~1 \jtlllCfi[eil4l<:l -q <li0tmn q'i'<'4ff1\i1 1<11 <1 1* Cfi1 41 '5. quri-Tj (tA). eR:s1M\. ('1m ~ ~ ~ ~ ~ l:lT'l3l11ffiffitlm fcl>m 7T<n ~ I q'i,;qff1\i1ld \WI <), 3Rf1ffi 'lefn:l. 'lei quri-Tj (tA). "T*l10i mq; I THE term Cathaysia flora was proposed by Halle Palaeozoic flora of Cathaysia. (1935) and it was the name used on Grabau's The Cathaysia flora is one of the most famous palaeogeographical maps for the Palaeozoic land-mass floras of the Carboniferous and the Permian in the in East Asia. Halle gave the term Cathaysia flora for world, which is mainly distributed in present-day the entire Carboniferous and Permian plant China, Korea, Japan, Laos, Thailand, Indonesia and succe~sions in East Asia. Previously, the Cathaysia Malaysia. It is characterized by the genera flora could also be considered as the Gigantopteris Cathaysiodendron, Lobatannularia, Tingia, Yuania, flora. According to Halle, the Cathaysia flora is not Conchophyllum, Rajahia, Fascipteris, Emplectopteris, synonymous with the Gigantopteris flora, because the Empleetopteridium, Cathaysiopteris, Gigantopteris, latter corresponds to only the last phase of the Gigantonoclea, Ot%lium and a considerable number KEQIN & CHANDRA-EVOLUTION AND ECOLOGY OF THE CATHAYSIA FLORA 21 of endemic species, namely, Lepidodendron oculusfelis, fructiferous organ genera, including Peetinangium, L. posthumii, L. szeianum, SphenophyLlum sino­ Gigantonomia, Gigantotheca and Distchotheca, none of coreanum, Annularia orientalis, Pecopteris taiyuanensis, which have ever been found in the northern floral Alethopteris norinii, CaLlipteridium koraiense, subprovince. Meanwhile, some peculiar organ genera Psaronium sinensis, Taeniopteris mucronata, are commonly known in North China such as Pterophyllum daihoense, Psygmophyllum multiparti­ Nystroemia, Asterocupulites and some unique plants, tum, etc. China is the most important locality for the including Pseudorhipidosis, Procycas, Primocycas, etc. Cathaysia flora in Asia. The Cathaysian floral province which are hitherto not seen in the southern floral can be divided into the northern and southern floral subprovince (Li Xingxue et al., 1995). However, it is sub provinces in China (Li Xingxue & Yao Zhaoqi, noteworthy that OtoJolium and Rajahia have been 1985). The northern floral subprovince is located in recorded in the northern subprovince (Shen northern China. The Carboniferous and Permian Guanglong, 1995). It is worth emphasizing that some strata are well developed in northern China, which typical Cathaysian genera, such as Gigantopteris, are ch.lracterized by marine-terrestrial transitional OtoJolium and Rajahia are of very rare occurrences in facies and terrestrial facies including a number of major the northern floral subprovince, while Empleetopteris coalfields, such as those of Hebei, Shanxi, Inner and Yuania are restricted to rare appearances in the Mongolia, Shandong, Liaoning, Ningxia, Gansu, etc. southern floral subprovince. So far, Emplectopteridium The southern floral subprovince occupies a vast area has never been recorded in the southern floral in southern China. The Upper Carboniferous subprovince. Minor differences between the northern sequences in southern China are almost completely floral subprovince and southern floral subprovince marine and no evidences of reliable fossil plants are reflect variations of floristic composition and recorded. The Permian sequences of the subprovince terrestrial ecosystem in time and space. In addition, are characterized by marine and non-marine some mixed floras between the Cathaysia province alrernating coal-bearing deposits, which are mainly and Gondwana province are also distributed in Hazro distributed in Hunan, Fujian, ]iangxi, Guangdong, of Anatolia in Turkey, New Guinea, Kashmir and ]iangsu, Yunnan, Guizhou, Hunan, Sichuan, etc. The South Tibet. Thus, although the nature of the northern subpovince and southern subporvince were Cathaysia flora is quite different from that of the located in the equatorial region under a tropical climate Gondwana flora, the boundary between them seems during the Carboniferous and Permian. Therefore, to be more closely related. The distribution of the their similarity is reflected by a number of identical mixed floras was controlled by climatic conditions, Cathaysian genera, such as Cathaysiodendron, plate tectonics and continental positions. Lobatannularia, Tingia, Yuania, Fascipteris, Cathaysiopteris, Gigantonoclea, Gigantopteris, etc. and EVOLUTION OF THE CATHAYSIA FLORA numerous common endemic species, viz, Seeing that the flora of the early Late Lepldodendron oculusJelis (Abbado) Zeiller, Carboniferous (Namurian Band C) of the Cathaysia SphenophyLlum sino-coreanum Yabe, A nnularia area was characterized by a variety of oriental lycopods mucronata Schenk, Plagiozamites oblongiJolius Halle, and many endemic elements of ferns and Pecopteris lativenosa Halle, Cladophlebis nystroemii pteridosperms, Sun Keqin (1993a, 1995 1996), Mi Halle, Alethopteris norinii Halle, Protoblechnum ]iarong and Sun Keqin (1995) put forward that the wongii Halle, Odontopteris subcrenulata Halle, Cathaysia flora derived from the Lepidodendropsis Cladophlebis nystroemii Halle and Taeniopteris flora of Early Carboniferous in the world and pointed nystroemii Halle etc. The Upper Permian of the South out that the Cathaysia flora had become an China also contains a number of endemic form-genera, independent flora in the early Late Carboniferous including Rajahia and OtoJolium (Cleal & Thomas, (Namurian B to C). The Cathaysia flora ranged from 1991). The southern floral subprovince is distinguished the beginning of the early Late Carboniferous to the by such special genera as Rajahia, OtoJolium and some end of the Permian in age (Sun Keqin, 1996). 22 THE PALAEOBOTAN5T It is known that the Lepidodendropsis flora of Wu, Tingia triLobata Stockmans et Msthieu, the Early Carboniferous is widely distributed all over ConchophyLLum richto/enii Schenk, etc. (Zhao Xiuhu the world and has similarities on a global scale. and WU Xiuyuan, 1982: Mi ]iarong et aL., 1990; Wu ]ongmans (1952, 1954) considered that all Early Xiuyuan, 1992; Chen Fen et aL., 1995; Chen Fen and Carboniferous plant assemblages belonged to the same Sun Keqin, 1996). phytogeographic province on the basis of the In the early Late Carboniferous