Bryophyte-like Fossil (Parafunaria sinensis) from Early-Middle Cambrian Kaili Formation in Guizhou Province, China

Size: px

Start display at page:

Download "Bryophyte-like Fossil (Parafunaria sinensis) from Early-Middle Cambrian Kaili Formation in Guizhou Province, China"

Deirdre Campbell
6 years ago
Views:

1 Acta Botanica Sinica 2004, 46 (2): Bryophyte-like Fossil (Parafunaria sinensis) from Early-Middle Cambrian Kaili Formation in Guizhou Province, China YANG Rui-Dong, MAO Jia-Ren, ZHANG Wei-Hua, JIANG Li-Jun, GAO Hui (Guizhou University of Technology, Guiyang , China) Abstract: Abundant well-preserved animal and macroalgal fossils were discovered in the Early-Middle Cambrian Kaili Formation of Taijiang County, Guizhou Province, China, which constitute the Kaili Biota, named as one of the three important Burgess Shale-type faunas. The bryophyte-like fossil (Parafunaria sinensis Yang gen. et sp. nov) was discovered in the horizon of occurrence of Macroalgal fossils. The fossil of P. sinensis possesses typical characters of bryophyte, such as whorled leaves, capsule and seta, and complex rhizoid or foot. We infer that the bryophyte-like fossil could be the ancestor of bryophyte. The discovery provides a new lead for further study on the origin and evolution of bryophyte or land plant. Key words: bryophyte-like fossil; Kaili Formation; Middle Cambrian; Guizhou Province The origin and evolution of land plant is one of the unsolved evolution events of earth s life. Of the plant fossils being discovered, cryptospore assemblage from the lower Middle Ordovician (476 Ma) of Saudi Arabia was considered as the earliest land plant (Strother et al., 1996). In 1999, Strother, an American paleontologist reported the oldest cryptospore assemblage from the Middle Cambrian of North America (Strother and Wood, 1999). Thereafter, the earliest vascular plant fossil from the Middle Ordovician of North Europe was determined (Hao et al., 2002). Pinnatiramosus qianensis (Geng, 1986) from the Llandoverian (431 Ma) of Early Silurian of Fenggang County, Guizhou Province, China was claimed to be the oldest macro land plant fossils (Cai et al., 1996). Isotopic carbon (δ 13 C) values from the Neoproterozoic Beck Spring Dolomite and Mesoroterozoic Mescal Limestone paleokarst show that the land plant was present Ma ago (Kenny and Knauth, 2001), whereas molecular clock estimates suggest that the early land plant appeared by 700 Ma (Heckman et al., 2001). Obviously, the oldest record of the land plant fossil in the geological time is much younger than that of the land plant in the divergence time estimated in molecular clock, δ 13 C and molecular paleontology. Therefore, paleontologists constantly consider that the vascular plant fossils should exist in the pre-middle Ordovician strata. The discovery of the bryophyte-like fossil Parafunaria sinensis from the Middle Cambrian Kaili Formation in Guizhou Province, China not only provides an important evidence for the above-mentioned viewpoint, but also a new lead for further study on the origin and evolution of bryophyte or land plant. 1 Locality and Age of the Fossil Because sea-level fell during the interval of the Early- Middle Cambrian the slop facies, along the range of Sanhui-Taijiang-Danzhai of the eastern Guizhou Province, developed the Kaili Formation composed of terrestrial clastic rock, simultaneously, the shallow facies of the range of Sanhui-Kaili-Danzhai might form some little islands. A lot of animals and algae lived around the small islands or on the upper part of the slop. Based on the ecological behaviors of animals and algae, and their characteristics of deposition and the geochemical parameter, it can be considered that most animals and algae in the Kaili Biota lived in the shallow water, and these organisms were carried into the slop or shelf by tempest or turbidity flow and buried in the slop or shelf. Therefore, the Kaili Biota (Lagerstätte) is only a window to understand the Middle Cambrian life. The Balang section is 270 km far from Guiyang City, Guizhou Province of Southwest China (Fig.1A), which consists of mudstones and calcareous mudstones bearing abundant intact animal and alga fossils which constitute the Kaili Biota including 12 phyla, and about 120 genera (Zhao et al., 1994), in which about 20 genera belonging to macroalgae (Yang et al., 1999; 2000; 2001a; 2001b). The fossils of the Kaili Biota were collected from the middle part of the Xingrenaspis-Oryctocephalus Zone in the middle of the Kaili Formation of the Lower-Middle Cambrian (Fig.1B) (Zhao et al., 1994). The bryophyte-like fossils described in this paper were collected from the Kaili Biota, about 1 m Received 14 Jun Accepted 20 Oct Supported by the National Natural Science Foundation of China ( ), the State Key Basic Research and Development Plan of China (2002CCC02600) and the Guizhou Foundation of the Excellent Youth Scientists and Technicians. * Author for correspondence. <yangruidong@21cn.com>.

2 YANG Rui-Dong et al.: Bryophyte-like Fossil (Parafunaria sinensis) from Early-Middle Cambrian Kaili Formation Fig.1. Regional locality and horizon of the bryophyte-like fossil Parafunaria sinensis from the Early-Middle Cambrian Kaili Formation of Taijiang County, Guizhou Province, China. over the horizon of the first appearance of Oryctocephalus indicus (key fossil for the Middle Cambrian). So, the age of the bryophyte-like fossil P. sinensis from the Kaili Formation in Guizhou Province, China certainly is of the Middle Cambrian. 2 Fossil Description The bryophyte-like fossil Parafunaria sinensis Yang gen. et sp. nov (Fig.2A D) from the Kaili Formation of Taijiang County, Guizhou Province, China was preserved within the mudstones and calcareous mudstones deposited in the shelf or the upper part of the slop. The bryophyte-like fossil was preserved in carbonaceous form, which looks like the carbonaceous alga fossils of the Kaili Biota. Kingdom Bryophyta? Division? Musci? Class, Order, Family uncertain Genus Parafunaria gen. nov Etymology: The fossil is similar to the living Funaria. Material: 12 specimens with intact thalli collected by Yang and Zhao from the Kaili Formation, together with many dissociated fragments. Holotype: Intact thallus, GTM ; Fig.2B, collected from the Middle Cambrian Kaili Formation of Taijiang, Guizhou Province, China. Noncalcareous. The color of the specimens is pale-brown to dark-gray. Occurrence: The Middle Cambrian Kaili Formation of Taijiang, Guizhou Province, China. Type species: Parafunaria sinensis Yang, sp. nov. (specimen No. GTM ; Fig.2B) Description Carbonaceous thallus, 4 5 whorled leaves or crowd leaves, leaf long, obvious costa, no midcosta, short stem, complex rhizoid or foot, and with capsule and seta. The thallus is 2.0 cm in length, 0.8 cm in width. Stem 1.5 mm in length. Leaf 5 15 mm in length, and 5 mm in width. Discussion The morphology of the fossil has not been reported. According to its morphology featuring with 4 5 whorled leaves, and obvious costa, complex rhizoid or foot, capsule and seta, it seems to be comparable with the living Funaria hygrometrica Hedw (Wu et al., 1990; Taylor, 1981). Therefore, the authors proposed that Parafunaria sinensis Yang, gen. et sp. nov. could be a bryophyte fossil. The oldest bryophyte fossil Pallavicinites (=Hepaticites) from Late Devonian of New York has been previously reported (Huber, 1961; Schuster, 1966). The bryophyte-like fossil Sporogonites from the Early Devonian of Norway (Halle, 1916; Andrews, 1960), and Tortilicaulis from the Late Devonian of South-West Dyfed have certain affinity for bryophyte (Edwards, 1979; Taylor, 1981). The fossil of

Fig.2. The bryophyte-like fossil Parafunaria sinensis and cryptospore fossils from the Kaili Formation of the Middle Cambrian, Guizhou Province, China. A. P. sinensis, with complete rhizoid, veins; specimen No.

GTM-9-5-123. E. Nodospora sp., specimen No. P-6, X800. F. Dyadospora sp., specimen No. P-6, X800. G and H. structural sketch of the specimens No. GTM-9-2-113 and No. GTM-9-1-168.

3 Fig.2. The bryophyte-like fossil Parafunaria sinensis and cryptospore fossils from the Kaili Formation of the Middle Cambrian, Guizhou Province, China. A. P. sinensis, with complete rhizoid, veins; specimen No. GTM B. type species: P. sinensis, with the feature of capsule and seta, specimen No. GTM C. P. sinensis, with costa, specimen No. GTM D. P. sinensis, specimen No. GTM E. Nodospora sp., specimen No. P-6, X800. F. Dyadospora sp., specimen No. P-6, X800. G and H. structural sketch of the specimens No. GTM and No. GTM Scale in A, B, C, D, G, H for 1 cm. Sporogonites yunnanense Hsu from Devonian of eastern Yunnan, as the cryptospores of genus Andreaea was found in 1966 (Xu, 1966). Zhang (1988) suggested that Longfengshania of Proterozoic Changlongshan Formation is morphologically similar to Sporogonites; thus, he considered that Longfengshania has affinity to bryophyte. P. sinensis is similar to the Devonian Pallavicinites and Sporogonites in structure, such as whorled leaves, and obvious costa, complex rhizoid or foot, and the feature of capsule and seta. But it is different from the Devonian Pallavicinites and Sporogonites in morphology. Fossil P. sinensis is small, and possesses 4 5 whorled leaves only which fossils Pallavicinites and Sporogonites from Devonian are larger, and possesses over 10 whorled leaves (Andrews, 1960; Schuster, 1966; Xu, 1966). Moreover, fossil P. sinensis possesses obvious costa. The fossil P. sinensis is similar to the living Bryum in the presence of whorled leaves, and obvious costa, complex rhizoid or foot, and the feature of capsule and seta, but the living Bryum (bryophyte) possesses obvious and long stem, nevertheless the fossils with short and unobvious stem (Fig.2G, H) from the Kaili Formation is even more similar to

4 YANG Rui-Dong et al.: Bryophyte-like Fossil (Parafunaria sinensis) from Early-Middle Cambrian Kaili Formation the living Funaria hygrometrica Hedw (bryophyte). In 1997, Bian and Ynag discovered a typical bryophyte fossil Tarimia leei from the Late Ordovician in Tarimia Basin, Xinjiang, China. This specimen is 2.8 cm in length, with about 60 leaves, whorled or spiral, the feature of capsule and seta, and no mid-costa. The fossil is possibly the oldest bryophyte fossil reported previously, and it is similar to the living Bryum (bryophyte). 3 Significance of the Bryophyte-like Fossil in the Evolution of the Vascular Plant The origin and evolution of the vascular plant has been long-time under debate. Since bryophyte is the oldest land plant and vascular plant, Cambrian bryophyte fossils become important in the study of the origin and evolution of land plants. Because bryophyte plant is too small in size for fossil preservation, and the bryophyte fossils are almost rare in strata; thus the palaeontologists have difficulty to define the origin of the bryophyte. Therefore, based on the morphological and anatomical features of bryophyte, two views upon the origin of bryophyte have been put forward (Taylor, 1981; Wu et al., 1990). The first view suggests that the bryophyte originates from Chlorophyte (Wu et al., 1990), as both bryophyte and Chlorophyte possess the same chlorophyll and xanthophylls, additionally, in the modern Chlorophyta, Fritschiella tuberosa and Takakia lepidozioides have obvious affinities with bryophyte in morphology and structure (Wu et al., 1990). The second view considers that the bryophyte originates from Psilophyton, based on genus Rhynia and genus Psilophyton of Pteridophyta having obvious affinities with bryophyte in morphology and structure, and the age (Silurian) of pteridophyte fossils previously found being older than that (Devonian) of bryophyte fossils (Taylor, 1981). Nevertheless, the bryophyte fossils discovered are too rare to satisfy the needs of research. The bryophyte-like fossil P. sinensis discovered in the Middle Cambrian strata, infer that bryophyte might have emerged in Cambrian. Since Psilophyton (Pteridophyta) fossils discovered previously are from the post-cambrian, on the basis of geological time of the fossil record, the oldest Psilophyton (Pteridophyta) fossil discovered previously is in Silurian, and bryophyte fossils discovered previously are in Ordovician, while the present bryophyte-like fossil discovered is in the Middle Cambrian, it infers that bryophyte did not originate from Psilophyton Bian L-Z( ), Yang R-D( ) The bryophyte fossils from Late Ordovician in Talimu Basin, Xinjiang. Research report. (Pteridophyta). In contrast, because Psilophyton (Pteridophyta) possesses obvious and robust stem, as compared with the unobvious and short stem of the bryophyte, thus, Psilophyton (Pteridophyta) possibly originates from bryophyte. However this view merits further fossil study for confirmation. Gray, Burgess, Strother and Wellman respectively suggested that the plant existed in the Late Ordovician to Early Silurian based on the findings of cryptospore fossils in the Late Ordovician and Early Silurian (Gray and Boucot, 1977; Strother and Traverse, 1979; Burgess and Edwards, 1991; Wellman, 1995). Volkheimer et al.(1980) reported the bryophyte-like cryptospores from the Mojotoro Formation of the Early Ordovician and Argenigian of Prague basin (Vavrdova, 1990). Strother et al. (1996) reported a new evidence for land plants from the lower Middle Ordovician of Saudi Arabia in The evidence of fossil P. sinensis from the Middle Cambrian Kaili Formation of Taijiang and the cryptospore fossils Fig.2E, F from the Middle Cambrian Kaili Formation of Danzhai County, Guizhou Province, China indicate that bryophyte was probably present in the Middle Cambrian. The cryptospore fossils Fig.2E, F from the Middle Cambrian Kaili Formation of Danzhai County, Guizhou Province, China consist of imperfectly spores, tetrads and dyads similar to the plant microfossil Lophodiacrodium Strother et al.,1996, pl.1,figs.9,12; pl.2, fig.1 from Llandoverian and Wenlockian rocks of Pennsylvania (Strother and Traverse, 1979). Nevertheless, the cryptospore fossils are still a problem merits further study. The discovery of the Middle Cambrian bryophyte-like fossil and the cryptospore fossils indicate that bryophyte was probably present in the Middle Cambrian (520 Ma), and provides a new lead for further study on the origin and evolution of bryophyte or land plant. 4 Conclusion The oldest bryophyte fossils from Devonian (Xu, 1966) or Late Ordovician (Bian and Yang, 1997) has been previously reported, but the oldest cryptospore fossil discovered may be traced back to Cambrian (Strother and Wood, 1999). The Middle Cambrian bryophyte-like fossil and the cryptospore fossils from Guizhou Province, South China were discovered, indicating that bryophyte was probably present in the Middle Cambrian (520 Ma), therefore, the bryophyte-like fossil from Guizhou Province, South China is the oldest bryophyte fossil ever known. The discovery infers that the age of origin of bryophyte is 50 Ma earlier than that being considered before. Based on that

5 Pteridophyta and Chlorophyta have affinities with bryophyte in morphology, and on account of the fossil records of Pteridophyta, Chlorophyta and Bryophyta in the geological time, we infer that bryophyte originates from chlorophyte because chlorophyte fossil has been discovered in Precambrian, and pteridophyte originates from bryophyte because the oldest pteridophyte fossil having discovered previously is in Devonian. Acknowledgements: The authors wish to thank Prof. YIN Lei-Ming, Prof. ZHAO Yuan-Long and BIAN Li-Zeng for their help in this study. References: Andrews H N Jr Notes on Belgium specimens of Sporogonites. Palaeobotanist, 7: Burgess N D, Edwards D Classification of uppermost Ordovician to Lower Devonian tubular and filamentous macerals from the Arglo-Welsh Basin. Bot J Linn Soc, 106: Cai C Y, Ouyang S, Wang Y, Fang Z J, Rong J Y, Geng L Y, Li X X An Early Silurian vascular plant. Nature, 379:592. Edwards D A Late Silurian flora from the Lower Old Red Sandstone of South-West Dyfed. Palaeontology, 22: Geng B-Y Morphologic and anatomic feature of Pinnatiramosus qianensis (gen. nov.) from Guizhou Middle Silurian. Acta Bot Sin, 28: (in Chinese with English abstract) Gray J, Boucot A J Early vascular land plants: proof and conjecture. Lethaia, 10: Halle T G Lower Devonian plants from Roragen in Norway, Kungl. Svenska Vet Handl, 57:3 46. HAO S-G, WANG D-L, WANG Q The origin of land plants and the early evolution of land vascular plants. Acta Sci Nat Univ Pekinensis, 38: Heckman D S, Geiser D M, Eidell B R, Stauffer R L, Kardos N L, Hedges S B Molecular evidence for the Early colonization of land by fungi and plants. Science, 293: Huber F M Hepaticites devonicus, a new fossil liverwort from the Devonian of New York. Ann Missouri Bot Gard, 48: Kenny R, Knauth L P Stable isotope variations in the Neoproterozoic Beck Spring Dolomite and Mesoroterozoic Mescal Limestone paleokarst: Implications for life on land in the Precambrian. GSA Bulletin, 113: Schuster R M The Hepaticae and Anthocerotae of North America east of the hundredth meridim, Vol. I. New York: Columbia Book Compary, Strother P K, Al-Hajri S, Traverse A New evidence for land plants from the lower Middle Ordovician of Saudi Arabia. Geology, 24: Strother P K, Wood G A terrestrial flora by Middle Cambrian time: evidence from the Bright Angel shale and Rogersville shale of the United States. the 32nd Annual Meeting of the American Association of stratigraphic palynologists. Savannah, Georgia. 14. Strother P K, Traverse A Plant microfossils from Llandoverian and Wenlockian rocks of Pennsylvania. Palynology, 3:1 20. Taylor T N Paleobotany-An Introduction to Fossil Plant Biology. New York: McGraw-Hill Book Company, Vavrdova M Early Ordovician acritarchs from the locality Myto near Rokycany. Casopis pro Mineralogii a Geologii, 35: Volkheimer W, Melendi D L, Acenolaza F G An Ordovician microflora from the Mojotoro Formation, Salta Province. Associati n Geol gica Argentina, Revista, 35: Wellman C H Cryptospores from the type area for the Caradoc Series (Ordovician) in southern Britain. Palaeontology, 38: Wu G-F, Feng Z-J, Ma W-L, Zhou X-J, Lang K-C Botany. Beijing: The High Education Press House (in Chinese) Xu R Devonian plant fossils in Yunnan Province, China: Implications for stratigraphic correlation and division of Devonian. Acta Bot Sin, 14: (in Chinese with English abstract) Yang R-D, Zhao Y-L, Guo Q-J, Shi G-J Early Middle Cambrian Macroalgal fossils from Taijiang county, Guizhou, China. Geol Rev, 45: (in Chinese with English abstract) Yang R-D, Zhao Y-L Discovery of Corallina fossil from the Middle Cambrian of Taijiang country, Guizhou province, China. Chin Sci Bull, 45: Yang R-D, Mao J-R, Zhao Y-L. 2001a. New macroalgal fossils from Middle Cambrian Kaili biota in Guizhou Province, China. Acta Bot Sin, 43: Yang R-D, Mao J-R, Zhao Y-L, Chen X-Y, Yang X-L. 2001b. Branching macroalgal fossils of the Early-Middle Cambrian Kaili Formation from Taijiang, Guizhou Province, China. Acta Geol Sin, 75: (in Chinese with English abstract) Zhang Z-Y Longfengshania Du emend an earliest record of bryophyte-like fossils. Acta Palaeontol Sin, 27: (in Chinese with English abstract) Zhao Y-L, Yuan J-L, Huang Y-Z, Mao J-R, Qian Y, Zhang Z-H, Gong X-Y Middle Cambrian Kaili fauna in Taijiang, Guizhou. Acta Palaeontol Sin, 33: (in Chinese with English abstract)

Leaf-like Rhodophycean Fossils in the Early Cambrian from Haikou, Kunming, Yunnan of China

Acta Botanica Sinica 2004, 46 (11): 1276-1280 http://www.chineseplantscience.com Leaf-like Rhodophycean Fossils in the Early Cambrian from Haikou, Kunming, Yunnan of China XU Zhao-Liang (Laboratory of