Skip to main content Accessibility help

A problematic animal fossil from the early Cambrian Hetang Formation, South China

  • Qing Tang (a1), Jie Hu (a2), Guwei Xie (a3) (a4) (a5), Xunlai Yuan (a6) (a7), Bin Wan (a6), Chuanming Zhou (a8), Xu Dong (a9), Guohua Cao (a9), Bruce S. Lieberman (a10), Sally P. Leys (a11) and Shuhai Xiao (a1)...


The lower-middle Hetang Formation (Cambrian Stage 2–3) deposited in slope-basinal facies in South China is well known for its preservation of the earliest articulated sponge fossils, providing an important taphonomic window into the Cambrian Explosion. However, the Hetang Formation also hosts a number of problematic animal fossils that have not been systematically described. This omission results in an incomplete picture of the Hetang biota and limits its contribution to the understanding of the early evolution of animals. Here we describe a new animal taxon, Cambrowania ovata Tang and Xiao, new genus new species, from the middle Hetang Formation in the Lantian area of southern Anhui Province, South China. Specimens are preserved as carbonaceous compressions, although some are secondarily mineralized. A comprehensive analysis using reflected light microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and micro-CT reveals that the new species is characterized by a spheroidal to fusoidal truss-like structure consisting of rafter-like crossbars, some of which are secondarily baritized and may have been internally hollow. Some specimens have aperture-like structures that are broadly similar to oscula of sponges, whereas others show evidence of a medial split reminiscent of gaping carapaces. While the phylogenetic affinity of Cambrowania ovata Tang and Xiao, n. gen. n. sp. remains problematic, we propose that it may represent carapaces of bivalved arthropods or more likely sponges in early life stages. Along with other problematic metazoan fossils such as hyolithids and sphenothallids, Cambrowania ovata Tang and Xiao, n. gen. n. sp. adds to the diversity of the sponge-dominated Hetang biota in an early Cambrian deepwater slope-basinal environment.




Hide All
Botting, J.P., and Muir, L.A., 2018, Early sponge evolution: A review and phylogenetic framework: Palaeoworld, v. 27, p. 129.
Botting, J.P., Muir, L.A., Xiao, S., Li, X., and Lin, J.-P., 2012, Evidence for spicule homology in calcareous and siliceous sponges: Biminerallic spicules in Lenica sp. from the early Cambrian of South China: Lethaia, v. 45, p. 463475.
Botting, J.P., Yuan, X., and Lin, J.P., 2014, Tetraradial symmetry in early poriferans: Chinese Science Bulletin, v. 59, p. 639644.
Braun, A., Chen, J., Waloszek, D., and Maas, A., 2007, First early Cambrian Radiolaria, in Vickers-Rich, P., and Komarower, P., eds., The Rise and Fall of the Ediacaran Biota: London, Geological Society of London, Special Publications, p. 143149.
Briggs, D.E.G., Liu, H.P., McKay, R.M., and Witzke, B.J., 2015, Bivalved arthropods from the Middle Ordovician Winneshiek Lagerstätte, Iowa, USA: Journal of Paleontology, v. 89, p. 9911006.
Bureau of Geology and Mineral Resources of Anhui Province, 1987, Regional Geology of Anhui Province. Chinese Ministry of Geology and Mineral Resources, Geological Memoirs, series 1, number 5: Beijing, Geological Publishing House, 721 p.
Cai, Y., Xiao, S., Li, G., and Hua, H., 2019, Diverse biomineralizing animals in the terminal Ediacaran Period foreshadow the Cambrian Explosion: Geology, doi .org /10.1130/G45949.1.
Chen, Z., Hu, J., Zhou, C., Xiao, S., and Yuan, X., 2004, Sponge fossil assemblage from the early Cambrian Hetang Formation in southern Anhui: Chinese Science Bulletin, v. 49, p. 16251628. [in Chinese with English summary]
de Cook, S.C., and Bergquist, P.R., 2002, Family Irciniidae Gray, 1867, in Hooper, J.N.A., Van Soest, R.W.M., and Willenz, P., eds., Systema Porifera: A Guide to the Classification of Sponges: Boston, Springer, p. 10221027.
Dong, L., Song, W., Xiao, S., Yuan, X., Chen, Z., and Zhou, C., 2012, Micro- and macrofossils from the Piyuancun Formation and their implications for the Ediacaran-Cambrian boundary in southern Anhui: Journal of Stratigraphy, v. 36, p. 600610. [in Chinese with English summary]
Dong, X., Cunningham, J.A., Bengtson, S., Thomas, C.-W., Liu, J., Stampanoni, M., and Donoghue, P.C.J., 2013, Embryos, polyps and medusae of the early Cambrian scyphozoan Olivooides: Proceedings of the Royal Society B: Biological Sciences, v. 280, 20130071.
Dong, X., Knoll, A.H., and Lipps, J.H., 1997, Late Cambrian Radiolaria from Hunan, China: Journal of Paleontology, v. 71, p. 753758.
Ehrlich, H., et al. , 2013, Discovery of 505-million-year old chitin in the basal demosponge Vauxia gracilenta: Scientific Reports, v. 3, p. 3497.
Erwin, D.H., and Valentine, J.W., 2013, The Cambrian Explosion: The Construction of Animal Biodiversity: Greenwood Village, Colorado, Roberts and Company, 406 p.
Erwin, D.H., Laflamme, M., Tweedt, S.M., Sperling, E.A., Pisani, D., and Peterson, K.J., 2011, The Cambrian conundrum: Early divergence and later ecological success in the early history of animals: Science, v. 334, p. 10911097.
Fu, D., and Zhang, X., 2011, A new arthropod Jugatacaris agilis n. gen. n. sp. from the early Cambrian Chengjiang biota, South China: Journal of Paleontology, v. 85, p. 567586.
Fu, D., Zhang, X., and Shu, D., 2009, Soft anatomy of the early Cambrian arthropod Isoxys curvirostratus from the Chenjiang biota of South China with a discussion on the origination of great appendages: Acta Palaeontologica Polonica, v. 56, p. 843852.
He, S., and Yu, G., 1992, The small shelly fossils from the Palaeocambrian Meishucunian Stage in western Zhejiang: Zhejiang Geology, v. 8, p. 17. [in Chinese with English summary]
Hill, M.S., et al. , 2013, Reconstruction of family-level phylogenetic relationships within Demospongiae (Porifera) using nuclear encoded housekeeping genes: PLoS ONE, v. 8, e50437.
Holmes, J.D., García-Bellido, D.C., and Lee, M.S.Y., 2018, Comparisons between Cambrian Lagerstätten assemblages using multivariate, parsimony and Bayesian methods: Gondwana Research, v. 55, p. 3041.
Hou, X., and Bergström, J., 1997, Arthropods of the Lower Cambrian Chengjiang fauna, southwest China: Fossils and Strata, v. 45, p. 1116.
Hu, J., Chen, Z., Yao-songWang, X., Jin-quanWang, J.Y., and Xun-lai, , 2002, Sponge spicules in early Cambrian Hetang Formation, Xiuning, southern Anhui: Acta Micropalaeontologica Sinica, v. 19, p. 5362. [in Chinese with English summary]
Knoll, A.H., and Carroll, S.B., 1999, Early animal evolution: Emerging views from comparative biology and geology: Science, v. 284, p. 21292137.
Leys, S.P., Kamarul Zaman, A., and Boury-Esnault, N., 2016, Three-dimensional fate mapping of larval tissues through metamorphosis in the glass sponge Oopsacas minuta: Invertebrate Biology, v. 135, p. 259272.
Li, C., He, J., and Ye, H., 1990, Discovery of early Cambrian trilobites in Guichi of Anhui Province: Journal of Stratigraphy, v. 14, p. 159160. [in Chinese with English summary]
Missarzhevsky, V.V., 1973, Konodontoobraznye organizmy iz pogranichnykh sloev kembriya i dokembriya Sibirskoj platformy i Kazakhstana [Conodont-shaped organisms from Precambrian–Cambrian boundary strata of the Siberian Platform and Kazakhstan]: Trudy Instituta Geologii i Geofiziki SO AN SSSR, v. 49, p. 5357. [in Russian]
Müller, E.B., 1894, Fauna und Flora des Golfes von Neapel und den angrenzenden Meers-Abschnitte: Herausgegeben von der Zoologischen Station zu Neapel, v. 21, p. 1104.
Muscente, A.D., and Xiao, S., 2015, Resolving three-dimensional and subsurficial features of carbonaceous compressions and shelly fossils using backscattered electron scanning electron microscopy (BSE-SEM): PALAIOS, v. 30, p. 462481.
Peng, S., Babcock, L.E., and Cooper, R.A., 2012, The Cambrian Period, in Gradstein, F.M., Ogg, J.G., Schmitz, M., and Ogg, G., eds., Geological Time Scale 2012: Oxford, Elsevier, p. 437488.
Qian, Y., and Yin, G., 1984, Small shelly fossils from the lowest Cambrian in Guizhou: Professional Papers of Stratigraphy and Palaeontology, v. 13, p. 91124 [in Chinese]
Steiner, M., Li, G., Qian, Y., Zhu, M., and Erdtmann, B.-D., 2003, Lower Cambrian small shelly faunas from Zhejiang (China) and their biostratigraphic implications: Progress in Natural Science, v. 13, p. 852860.
Steiner, M., Li, G., Qian, Y., Zhu, M., and Erdtmann, B.-D., 2007, Neoproterozoic to early Cambrian small shelly fossil assemblages and a revised biostratigraphic correlation of the Yangtze Platform (China): Palaeogeography, Palaeoclimatology, Palaeoecology, v. 254, p. 6799.
Tang, Q., Pang, K., Yuan, X., and Xiao, S., 2017, Electron microscopy reveals evidence for simple multicellularity in the Proterozoic fossil Chuaria: Geology, v. 45, p. 7578.
Topsent, E., 1927, Diagnoses d’Éponges Nouvelles recueillies par le Prince Albert ler de Monaco: Bulletin de l'Institut océanographique Monaco, no. 502, p. 119.
Vannier, J., Caron, J.-B., Yuan, J., Briggs, D.E.G., Collins, D., Zhao, Y., and Zhu, M., 2007, Tuzoia: Morphology and lifestyle of a large bivalved arthropod of the Cambrian seas: Journal of Paleontology, v. 81, p. 445471.
Voronova, L.G., and Missarzhevsky, V.V., 1969, Nakhodki vodoroslej i trubok chervej v pogranichnykh sloyakh kembriya i dokembriya na severe Sibirskoj platformy [Finds of algae and worm tubes in the Precambrian-Cambrian boundary beds of the northern part of the Siberian Platform]: Doklady AN SSSR, v. 184, p. 207210. [in Russian]
Walcott, C.D., 1899, Precambrian fossiliferous formation: Geological Society of America Bulletin 19, p. 199244.
Wu, W., Yang, A.-H., Janussen, D., Steiner, M., and Zhu, M.-Y., 2005, Hexactinellid sponges from the early Cambrian black shale of south Anhui, China: Journal of Paleontology, v. 79, p. 1403–1051.
Xiang, L., Schoepfer, S.D., Shen, S., Cao, C., and Zhang, H., 2017, Evolution of oceanic molybdenum and uranium reservoir size around the Ediacaran–Cambrian transition: Evidence from western Zhejiang, South China: Earth and Planetary Science Letters, v. 464, p. 8494.
Xiao, S., Hu, J., Yuan, X., Parsley, R.L., and Cao, R., 2005, Articulated sponges from the lower Cambrian Hetang Formation in southern Anhui, South China: Their age and implications for the early evolution of sponges: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 220, p. 89117.
Xue, Y., and Yu, C., 1979, Lithological characteristics and sedimentary environments of the lower Cambrian Hetang Formation in western Zhejiang and northern Jiangxi: Journal of Stratigraphy, v. 3, p. 283293. [in Chinese with English summary]
Yao, J., Xiao, S., Yin, L., Li, G., and Yuan, X., 2005, Basal Cambrian microfossils from the Yurtus and Xishanblaq formations (Tarim, north-west China): Systematic revision and biostratigraphic correlation of Micrhystridium-like acritarchs from China: Palaeontology, v. 48, p. 687708.
Yuan, X., Xiao, S., Parsley, R.L., Zhou, C., Chen, Z., and Hu, J., 2002, Towering sponges in an early Cambrian Lagerstätte: Disparity between nonbilaterian and bilaterian epifaunal tierers at the Neoproterozoic-Cambrian transition: Geology, v. 30, p. 363366.
Yuan, Y., Cai, C., Wang, T., Xiang, L., Jia, L., and Chen, Y., 2014, Redox condition during Ediacaran–Cambrian transition in the Lower Yangtze deep water basin, South China: Constraints from iron speciation and δ13Corg in the Diben section, Zhejiang: Chinese Science Bulletin, v. 59, p. 36383649.
Yue, Z., and He, S., 1989, Early Cambrian conodonts and bradoriids from Zhejiang: Acta Micropalaeontologica Sinica, v. 6, p. 289300. [in Chinese with English summary]
Yue, Z., and Zhao, J., 1993, Meishucunian (early Cambrian) rod-like fossils from western Zhejiang: Acta Micropalaeontologica Sinica, v. 10, p. 8997. [in Chinese with English summary]
Zhou, C., and Jiang, S., 2009, Palaeoceanographic redox environments for the lower Cambrian Hetang Formation in South China: Evidence from pyrite framboids, redox sensitive trace elements, and sponge biota occurrence: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 271, p. 279286.
Zhu, M., Zhuravlev, A.Y., Wood, R.A., Zhao, F., and Sukhov, S.S., 2017, A deep root for the Cambrian Explosion: Implications of new bio- and chemostratigraphy from the Siberian Platform: Geology, v. 45, p. 459462.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Paleontology
  • ISSN: 0022-3360
  • EISSN: 1937-2337
  • URL: /core/journals/journal-of-paleontology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed