Volume 63,Issue 4,2024 Table of Contents

1 A new type of Olivooides mirabilis from the Cambrian Kuanchuanpu Formation (Fortunian Stage, Terreneuvian Series), Ningqiang, Shaanxi Province

WANG Xiao-yang , CHEN Wei , YONG Yuan-yuan , CAI Yao-ping

2024, 63(4):415-429. DOI: 10.19800/j.cnki.aps.2024021

[Abstract](128) [HTML](0) [PDF 9.70 M](214)

Abstract:
Three-dimensionally phosphatized small shelly fossils with phylogenetic affinities of multiple animal phyla from the Fortunian strata of the Cambrian witnessed a pivotal evolutionary episode in the Cambrian Explosion. Olivooides is a morphologically distinctive and easily identifiable taxon in the small shelly fossil Anabarites trisulca tus–Protohertzina anabarica assemblage zone with a widely accepted phylogenetic placement within the Cnidarian. The great majority of Olivooides fossil specimens reported in the last 40 years have been primarily assigned to two species: O. multisulcatus and O. mirabilis. Morphological disparity and growth mode of Olivooides, however, need further study for better clarification. Here we describe phosphatized Olivooides fossils from the basal Cambrian Kuanchuanpu Formation (Fortunian Stage, Terreneuvian Series) at the Yuanbaoshan section in Ningqiang County, southern Shaanxi Province, South China. We report a new type of Olivooides mirabilis, characterized by only one transverse band in the embryonic tissue, five rows of tightly and sharply arranged longitudinal folds in the post-embryonic tissue, and two sets of oral lobes with two distinct degrees of folding. The distinct features between the new and the traditional O. mirabilis may represent intraspecific variation. The new fossil material adds to the diversity of Olivooides and sheds palaeobiological as well as embryological insights into our understanding of these enigmatic fossils in the earliest Cambrian Period.

2 Ontogeny of bivalved arthropod Mengdongella from the Furongian (upper Cambrian) of western Hunan

XIE Hao-wen , XIAN Xiao-feng , ZHANG Hua-qiao

2024, 63(4):430-443. DOI: 10.19800/j.cnki.aps.2024007

[Abstract](62) [HTML](0) [PDF 27.95 M](188)

Abstract:
Mengdongella is a microscopic bivalved arthropod found exclusively from the Paibian Stage (Furongian Series, upper Cambrian) of western Hunan, China. Due to the lack of specimens in different growth stages, previous studies are limited to morphological description of bivalved carapaces and functional analysis of valve spines, without investigating their growth process. In this paper, we present our in-depth study of the growth process of Mengdongella based on 229 specimens from the Bitiao Formation (Furongian) at the Wangcun section, Yongshun County, western Hunan. Specimens with different carapace sizes represent different growth stages. Detailed meas-urements and analyses reveal that there is a positive linear correlation between two of the following variables: valve length, valve height, valve spine length, and basal valve spine width. Thus, we propose that the carapace of Mengdongella shows allometry. Moreover, analysis on the valve length and valve height reveals discontinuous growth, indicating that Mengdongella has at least seven instars during its life span. The smallest individuals of Mengdongella are about 320 μm in length, belonging to meiofauna and possibly living in the space among sand grains or being pelagic, whereas larger individuals can reach at least 2.6 mm in length, belonging to macrofauna and living by creeping on the sea floor or swimming in the waters.

3 The phytocoenosium from the upper Carboniferous Taiyuan Formation of Wuda Coalfield, Inner Mongolia

GAO Zhuang , ZHOU Wei-ming , WAN Ming-li , WANG Jun

2024, 63(4):444-467. DOI: 10.19800/j.cnki.aps.2024011

[Abstract](63) [HTML](0) [PDF 38.71 M](217)

Abstract:
The Wuda Coalfield in Inner Mongolia yields over 40 coal seams within approximately 1500-meter-thick strata spanning from the Carboniferous to the Permian. The high-precision dating of volcanic tuff between No. 6 and No. 7 coal seams indicates an age of 298.34 Ma, nearly on the Carboniferous-Permian boundary. Taking advantage of the well exposure of the Taiyuan Formation in the Wuda Coalfield through open-pit mining, fossil plants have been extensively collected from No. 8 to No. 15 coal seams. Six plant-fossil bearing beds have been recognized, and 26 species of 14 genera of fossil plants have been identified. Based on sedimentological analyses, the plant assemblages of the upper Carboniferous Taiyuan Formation have been constrained well in palaeoecology, showing a typical phase of the middle stage of the Cathaysia Flora. The underclay of coal seams Nos. 12, 12^upper, 10, and 9 contain allochthonous plant fossils that indicate vegetation growing nearby the peat-forming swamp, whereas the roof shale of coal seam No. 8 yields autochthonous or parautochthonous plant fossils that represent the last phase of the coal-forming vegetation. The floristic difference between the floor beds of coal seams No. 12 to No. 9 may indicate that there exists the boundary of the traditionally well-known lower and upper plant assemblages of the Taiyuan Formation between coal seams No. 12^upper and No. 10. Moreover, the floristic difference between the roof shale of coal seam No. 8 and the volcanic tuff sandwiched between coal seams No. 7 and No. 6 indicates that the main peat-forming plants may vary with environmental changes during different stages of coal swamps–fossils in the underclay or roof shale may reflect the peat-forming vegetation or surrounding plant communities during the early or late stages of peat formation, whereas fossils found in the mid-stage of peat formation may differ in composition.

4 Rejuvenescences in Permian rugose coral Ipciphyllum naoticum in Xizang and their ecological implications

WANG Xiao-juan , CHI Hui-mei

2024, 63(4):468-478. DOI: 10.19800/j.cnki.aps.2024030

[Abstract](46) [HTML](0) [PDF 2.43 M](175)

Abstract:
This study focuses on the rejuvenescences in massive rugose coral Ipciphyllum naoticum from the Late Permian Gyanyima section in Xizang, southwest China. Two types of rejuvenescences, axial and lateral, are observed. Based on serial thin sections, the process of rejuvenescence is described. The skeletal characteristics of axial and lateral rejuvenescences in I. naoticum are significantly different, due to the regrowth of related corallite from different stages of ontogeny. The axial rejuvenated corallite regrow from an earlier juvenile stage. The diameter of the rejuvenated individuals significantly decreases, however, the axial columns of the original and rejuvenated corallites are not only continuous, but also have little change in size. This phenomenon may be due to the polyp being squeezed by adjacent polyps, reducing its space and making it more difficult to get sufficient food. Nutrient deficiency leads to a decrease in corallite diameter. The lateral rejuvenated corallite regrow from the brephic stage, and subsequently build new axial column, independent of the axial column of the original corallite. This phenomenon may be related to polyp health or injury. The regrowth of rejuvenated corals from the brephic stage or a younger stage depends on the overall condition of the polyp. If the polyp is relatively healthy, it may regrow from a younger stage. If only remnant tissue fragments survive, the rejuvenated coral may secrete skeleton from the brephic stage. In this study, the size of remnant tissue fragments of the lateral rejuvenated corallite that regrow from the brephic stage is limited. It can be inferred that the polyp fragments of some rugose corals, including I. naoticum, can also regrow like extant corals. In massive corals, individual rejuvenation may be related to the overall condition of the polyps, including injury and intraspecific competition, rather than the surrounding environment.

5 Trilobite studies in China: bibliometric research

REN Sai-chen , WANG Qing-shan , ZHANG Xing-liang

2024, 63(4):479-498. DOI: 10.19800/j.cnki.aps.2024025

[Abstract](83) [HTML](0) [PDF 5.63 M](206)

Abstract:
Trilobites are an extinct group of arthropods known only from the Paleozoic. They were abundant and diverse and had a worldwide distribution. Chinese scholars have been studying trilobites from China since 1924 and have made outstanding contributions to paleontology and stratigraphy of China. To reveal the past, present, and future trilobite research in China, we use CiteSpace citation visualization analysis software to measure the literatures on Chinese trilobites and carry out knowledge graph analysis. Data were collected from the Chinese Science and Technology Journal Database produced by CNKI, Wanfang Data Knowledge Service Platform, and Weipu Information Co., LTD., as well as the Web of Science core collection database, including 429 articles in Chinese database and 178 articles in English database. The results show that trilobite research in China has been increasing gradually with close institutional cooperation networks and gradual increase of international impact. Areas of trilobite research hotspots are in Guizhou, Yunnan, Hunan, Hubei, Anhui of the Yangtze Plate, and Hebei and Shandong of the North China Plate. The most targeted strata are the Cambrian and the Ordovician. The research topics of Chinese literatures focus on biostratigraphy, morphology and taxonomy, while those of English literatures are on ontogeny and biostratigraphy. The research methods have been becoming more diverse and interdisciplinary, involving geochemistry, ecology, fluid mechanics, etc. The cutting-edge research topics focus on the subfields of “ontogenetic molting”, “high-precision trilobite biostratigraphic framework”, and “trilobite diversity and macroevolution”, in combination with new technology such as Micro-CT. Overall, trilobite research has experienced an initial period (before 1965), a stagnation period (1966–1975), a rapid rise period (1976–1986), and a slow fluctuation period (1987–2023). It is urgent to increase talent acquisition and education in trilobite research, deepen interdisciplinary integration, expand the study of trilobites to the Qinghai-Tibet Plateau and other remote areas, and strengthen the study of trilobites from the Silurian–Permian strata. Future work may also concentrate on paleogeography, paleoecology, phylogeny, and macroevolution of trilobites from China.

6 Biological complexity in macroevolution

LI Yi-meng , ZHAO Fang-chen , ZENG Han , ZHU Mao-yan

2024, 63(4):499-512. DOI: 10.19800/j.cnki.aps.2024026

[Abstract](73) [HTML](0) [PDF 1.94 M](197)

Abstract:
Exploring the macroevolutionary processes of biological complexity from different perspectives is of great significance to the in-depth understanding of biological evolution. However, to accurately describe the evolutionary trend of biological complexity is challenging since biological complexity is difficult to define and quantify, and the model of analysis of evolutionary trends in biological systems is largely determined by its definition Based on previous studies of taxonomic diversity and morphological disparity, it is helpful to promote the in-depth study of macroevolutionary mechanism of organisms by exploring the biological complexity and its evolutionary trend and establishing the corresponding application models. Given that this research direction has not received widespread attention, this paper aims to deepen the understanding of the concept of biological complexity by reviewing the current status and development of the research on biological complexity, with the goal of promoting its application and development in paleontology and evolutionary biology.

7 A review on dating methods for ancient woods

LI Yu-feng , ZHANG Hou-jiang

2024, 63(4):513-525. DOI: 10.19800/j.cnki.aps.2024016

[Abstract](44) [HTML](0) [PDF 11.69 M](190)

Abstract:
Ancient woods hold significant historical, cultural, and scientific values due to their long history and widespread distribution. Dating ancient woods is essential for understanding and preserving wooden cultural relics, tracing the development of human civilization, and uncovering ancient climatic changes and ecosystem evolution. This paper introduces the principles of three scientific dating methods: radiocarbon (¹⁴C) dating, dendrochronological dating, and infrared/near-infrared spectroscopic dating. It also summarizes the current status of ancient wood dating research based on these three methods both domestically and internationally, and analyzes the advantages, limitations, and development directions of the three methods. In summary, radiocarbon dating is the most commonly used method, it may result in errors when applied to ancient woods. Dendrochronological dating is currently the most accurate method for dating ancient woods, but there is a lack of long tree-ring chronologies suitable for this purpose in China. Infrared/near-infrared spectroscopic technology, on the other hand, provides a promising new method for the dating of ancient woods. This paper is expected to inspire and assist those who are involved in the preservation and scientific research of wooden cultural relics.

8 3D reconstruction and optimization of fossil plants based on 3D printing: a case study of Nelumbo delinghaensis

WANG Guo-yi , HOU Si-ping , DAI Ai-bin , LUO Ming-yue , LI Qi-jia

2024, 63(4):526-536. DOI: 10.19800/j.cnki.aps.2023029

[Abstract](60) [HTML](0) [PDF 4.53 M](168)

Abstract:
Three-dimensional (3D) reconstruction and printing technology serve as important bridges between scientific research and public outreach in paleontology. However, compared with vertebrate fossils that are often preserved in three-dimensional form, plant fossils are often preserved in two-dimensional states due to their biological structures, making 3D printing and reconstruction more challenging. To address this issue, specimens of Nelumbo delinghaensis Luo et Jia, 2022, collected from the Miocene Qaidam Basin are used as a case study to explore a 3D printing-based method for reconstructing fossil plants. This approach aims to provide a new method for 3D reconstruction, presentation in paleobotanical research, and public engagement. After numerous attempts, a universal 3D printing workflow for reconstructing compression or imprint plant fossils is established. This workflow includes the processes of plant trait extraction, image processing, digital modeling, 3D printing, and post-printing treatment. In addition to outlining the workflow and methods, optimization strategies for the printing and post-processing steps are proposed based on the characteristics of the plant fossils. These strategies include the application of hollowing, packing lattice, and enhancement of details of fossils in reconstruction, all of which further enhance the authenticity and scientific value of the reconstructions. This approach provides a new way to showcase and study fossil plants, with great potential in research and educational activities in both scientific and public contexts.

Volume 63,Issue 4,2024 Table of Contents

Current Issue

Volume

Issue

Most Read

Most Cited

Most Downloaded

WeChat

Mobile website