Volume 60,Issue 3,2021 Table of Contents

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  • 1  Trace fossil: a significant agent for exploring organism-environment interactions
    LUO Mao GONG Yi-ming ZHANG Li-jun YIN Ya-fei
    2021, 60(3):347-356. DOI: 10.19800/j.cnki.aps.2020050
    [Abstract](727) [HTML](0) [PDF 2.17 M](2213)
    Abstract:
    Trace fossils record the behavioral characteristics of ancient organisms, and their preservations reflect the intimate interaction between organisms’ ethology, habitable substrates, and their living environments. In particular, soft-bodied organisms usually are difficult to be preserved in the fossil records, but their behaviors can be preserved as trace fossils. Thus, trace fossils are pivotal in reconstructing palaeoenvironmental and palaeoecological interpretations,deciphering the early evolution of life and the infaunal responses to environmental extremes during mass extinctions. This paper focuses on the advancement of the above mentioned ichnological research topics during the past ten years, and puts forward potential directions in future ichnological studies.
    2  Yunannioidea—a new superfamily of Pteriomorphids (Bivalvia) from the Middle Ordovician, Yunkai Area, western Guangdong, South China
    ZHANG Ren-jie NIU Zhi-jun LI Chu-an WANG Zhi-hong SONG Fang HE Yao-yan YANG Wen-qiang LIN Xiao-ming
    2021, 60(3):357-375. DOI: 10.19800/j.cnki.aps.2020026
    [Abstract](1012) [HTML](0) [PDF 40.22 M](25800)
    Abstract:
    The Ordovician in Yunkai area of western Guangdong Province mainly consists of sandstone, pelitic siltstone, silty mudstone and pebbly sandstone, and mudstone with intercalated carbonate rock lenses and conglomerates. The Ordovician includes the Lower Ordovician Luohong Formation and Luodong Formation, Middle Ordovician Dongchong Formation, and Upper Ordovician Lanweng Formation. Fossil bivalves, including the new taxa described in this paper, were collected from an about 2-meter-thick bed of gray to grayish yellow silty mudstone and pelitic siltstone of the upper part of the Dongchong Formation. The collection includes about one thousand bivalve specimens, which represent more than 22 species of 16 and several unnamed genera and may a possible new taxon. We report a group of unique bivalves including two new species of Yunannia gen. nov. of a new family Yunanniidae Zhang et Niu and a new superfamily Yunannioidea Zhang et Niu. This group demonstrate combined features normally attributed to different bivalve taxa. A small number of trilobites, including Nileus sp., Lonchobasilicus sp., Calymenesun tingi Sun, Calymenesun sp., Asaphopsis? sp., and brachiopods, including Paralenorthis sp., Aegira sp., Leptellina sp., Obolus? sp., Strophomena sp. and Nicolella sp., cooccur with the bivalves and indicate the Middle Ordovician age. SYSTEMATIC PALEONTOLOGYClass Bivalvia Linnaeus, 1758 in 1758–1759 Subclass Autobranchia Grobben, 1849 Infraclass Pteriomorphia Beurlen, 1944 Cohort Uncertain Superfamily Yunannioidea Zhang et Niu superfam. nov. Description Shell small, mytiliform, umbos anterior to terminal; strong inequilateral; buyssal sinus faint; the area beneath and anterior umbo edentulous; posterior to umbo a row of discrete chevron taxodont teeth; large anterior adductor muscle scar located in the umbonal angle and occupies the large and wide umbonal septum together with the anterior pedo-byssal retractors; posterior muscle scar unknown; external ligament, opisthodetic, submarginal; ligamental area narrow with 2-ranks of ligamental grooves and ridges, which are gently arched and extended continuously away from the dorsal margin; shell surface with faint comarginal growth lines. Remarks The Yunannioidea, a new superfamily of pteriomorphians is established based on the genus Yunannia proposed in the present paper. The Yunannia, the sole genus of the new superfamily Yunannioidea, is characterized by mytiliform outline, one posterior row of chevroned teeth, the large anterior adductor muscle scar located in the umbonal angle and inserted on the umbonal septum together with the anterior pedo-byssal retractor, and the arched two ranks of ligamental grooves and ridges which extend continuously away from dorsal margin. On the basis of features such as mytiliform, the musculature, and ligament, the Yunannioidea may be placed into the Cohort Mytilomorphi!. However, the genus Yunannia has only one row of posterior chevroned teeth. Together with its unusual hinge dentition, the new superfamily can be distinctly distinguished from other members of the same cohort. Meanwhile, features including the taxodont dentiotion and the two ranks of ligament indicate that Yunannia is likely in connection with Subcohort Ostreioni. Hence, the position of Yunannia at cohort level is undetermined. The genus Yunnania most possibly represents a new order of the infraclass Pteriomorphia. Family Yunannidae Zhang et Niu fam. nov. urn:lsid:zoobank.org:act:8A609836-4A82-4C6A-97B1-18168E761 891 Type genus Yunannia Zhang et Niu Yunannidae is the sole family of the new superfamily Yunannioidea. Distribution Middle Ordovician, Guangdong, China. Genus Yunannia Zhang et Niu gen. nov. urn:lsid:zoobank.org:act:B09DAFBA-A54D-4621-8FCD-07D8882 A6584 Type species Yunannia gankengensis Zhang et Niu gen. et sp. nov. Diagnosis Shell mytiliform, umbos anterior to terminal, with a row of posterior, discrete chevron taxodont teeth; anterior adductor muscle scar large and pedo-byssal retractor inserted on umbonal septum; ligament external and opisthodetic, extending continuously away from dorsal margin. Description The shell is small with height less than 21 mm. The shell shape is strongly inequilateral, mytiliform or narrow ovate with height longer than length. The umbos is anterior to terminal, projected and slightly incurved. Anterior lobe is absent. The dorsal-posterior margins are merged and widely arched. The anterior flange is thickened. The umbnal cavity is large and deep, separated by a lunate inner septum. The anterior adductor muscle scar is large and elliptical, located in the umbonalangle, and inserted on the umbanl septum together with the posteriorly extended pedo-byssal retractor. The growth line of anterior adductor muscle scar is present in one specimen. The anterior end of the anterior adductor scar is acuminate, likely marking the position of the pedal protractor but is obviously merged with the anterior adductor. The posterior adductor and posterior pedal retractor are unknown. The holotype, a left valve, bears about 20 teeth and sockets, while each half of a paratype bears about 8–15 teeth. The area anterior to and beneath umbo is edentulous. All teeth are discrete and chevroned with concavities towards distal end. The anterior two or three teeth are small and the rest become gradually larger posteriorly, achieving the maximum size about midway along the row of teeth. The teeth diminish gradually in size toward the posterior end of hinge plate. The ligament is external and opisthodetic, submarginal, sub-parallel to the gently arched dorsal-posterior shell margin. The ligamental area is narrow and extends posteriorly to about 3/4–4/5 height of shell, with one rather coarse ligamental ridge and two grooves above and below it (as the first-rank of ligament), while the weak and faint ligamental ridges and grooves (as the second-rank of ligament) within the first-rank ligamental grooves and ridge. Because of the number of first-rank ligamental groove-ridge couplets, it is likely the preduplivincular ligament. However, if the second-rank of ligament is also considered, the total number of ligamnental groove-rige couplets is more than two or three. Hence, it is likely the duplivincular ligament, rather than the preduplivincular ligament. In addition, the arched shape of ligamental area is similar to the simple arched ligament. The holotype specimen shows faint growth lines on the inner surface of shell wall. Etymology Yunan, a geographic name of a county in Guangdong Province. Remarks This genus is the sole representative of Yunannioidea superfam. nov. It is characterized by features such as the mytiliform shell having a posterior row of chevroned teeth, and the arched two ranks of ligamental groove-ridge couplets extending continuously away from the dorsal margin. The large anterior adductor located in the umbonal angle and inserted on the umbanl septum together with anterior pedo-byssal retractor. In addition, the large and wide umbonal septum is another distinguishing feature of Yunannia. The new genus combines some main features normally attributed to different bivalve taxa. Its dentition of taxodont teeth is similar to the Paleotaxodonta. The new genus and Ambonychioidea of Pteriomorphia share some features, including the mytiliform shape, terminal umbos and byssal sinus. Both the new genus Yunannia and cyrtodontoids have the same characteristic of sub-umbonaledentulous area. The present new genus and Dreissenoidea of Heteroconcha have common characters such as the anterior muscle scar inserted on umbonal septum, the submarginal, long, extended arched ligament. With the combination of features listed above, the new genus clearly distinguishes itself from all other genera in those taxa. Age and distribution Middle Ordovician; Guangdong, China. Yunannia gankengensis Zhang et Niu gen. et sp. nov. urn:lsid:zoobank.org:act:67E7B718-0211-4EBB-ADA9-898045A3 8637 (Figs. 3–5) Materials 8 specimens of internal moulds including 5 left valves and 3 right valves. Holotype: No. Ng4032, Paratypes: Ng4033, Ng4030, Ng4031, Ng1041. Diagnosis Height/length(width) ratio less than 1.5; ventral part of shell expanded and swollen. Description The shell is small, mytiliform, strongly inequilateral with height less than 20 mm. The height is longer than the length (width) with height/length(width) ratio less than 1.5. The umbos is terminal, projected and slightly incurved. The anterior lobe is absent. A faint byssal sinus is present at the upper part of anterior margin. The dorsal-posterior margins are merged and widely arched. A long and thickened anterior flange is present behind the anterior margin. A large umbnal cavity is separated by a lunate umbonal septum. The elliptical and large anterior adductor muscle scar is located in the umbonal angle, together with anterior pedo-byssal retractor, occupying the umbonal septum. The anterior adductor muscle scar being covered by growth line is showed in one paratype specimen (No. Ng1041). The anterior end of the anterior adductor scar is acuminate, which likely marks the position of the pedal protractor, but is obviously merged with the anterior adductor (as to otherwise indistinguishable). The posterior adductor and posterior pedal retractor are unknown. The area anterior to and beneath the umbo is edentulous. Posterior to the umbo there is a row of teeth consisting of 13–20 discrete and chevroned teeth with concavities towards the distal end. The anterior and posterior two or three teeth are small with the maximum size at the midway along the tooth row. The ligament is external and opisthodetic, submarginal, sub-parallel to the gently arched dorsal-posterior shell margin. The ligamenal area is narrow, extending posteriorly away from dorsal margin to about 4/5 height of the shell with one rather coarse ligamental ridge and two grooves laid above and below it (as the first rank of ligament), which are subdivided by the weak and faint (as the second rank) ligamental ridges and grooves. Because of the number of the first rank ligamental groove and ridge couplets, it is likely the preduplivincular ligament. However, if the second-rankof ligament is also considered, the total number of ligamnental groove-rige couplets is more than 2–3. Hence, it is likely the duplivincular ligament, rather than the preduplivincular ligament. Faint growth lines are present on the shell surface. Measurement Holotype: No. Ng4032: height 17.5 mm, length 13, H/L = 1.35. Etymology Gankeng, a geographic name of Guangdong. Comparison The present new species evidently differs from Yunannia yunkaiensis gen. et sp. nov. in having mytiliform shape, shell becoming gradually wider towards ventral side, with the maximum width near the ventral part of the shell, and a height/length ration less than 1.5. The latter species has a narrow and narrow ovate shape and a height/length ration about 2. Occurrence Gankeng Village, Yunan County, Guangdong Province; Dongchong Formation, Middle Ordovician. Yunannia yunkaiensis Zhang et Niu gen. et sp. nov. urn:lsid:zoobank.org:act:BE7BF3A3-3F07-4049-88F3-2EE989D4 E914 (Fig. 6) Materials 3 internal moulds of left valve. Holotype: No. Ng4035, Paratypes: Ng074, Ng4034. Diagnosis Shape narrow ovate and H/L ratio about 2.0. Description The shell is small, narrow ovate, strongly in-equilateral, 16.5–21 mm high. The height is much longer than the length with a H/L ratio of 2.0. The umbos is projected and slightly incurved. The anterior lobe is absent. The dorsal-posterior margins are merged and gently arched. The thickened anterior flange is relatively narrow. The umbonal cavity is separated by lunate, relatively narrow umbonal septum. The large and elliptical anterior adductor muscle scar is located in the umbonal angle, and together with the pedo-byssal retractor, inserted on umbanl septum. The anterior end of the anterior adductor scar is deeply inserted and becomes shallow poster-ventrally. The posterior adductor and posterior pedal retractor are unknown. The area anterior to and beneath umbo is edentulous with a posterior row of hinge tooth consisting of more than 8 to 13 discrete and chevroned teeth with concavities towards the distal end. The ligament is external and epithetic, submarginal. The ligamental area is narrow, sub-parallel to the gently arched dorsal-posterior shell margin, extending posteriorly away from dorsal margin to about 3/4 height of shell, and with one rather coarse ligamental ridge and two grooves above and below it (as the first rank of ligament). The four weak and faint ligamental groove-ridge couplets (as the second rank of ligament) extend about 5 mm in length in the dorsal side of the groove of the first rank ligament. Surface ornaments of the shell are unknown. Measurement Holotype: No. Ng4035; height 21 mm, length 10 mm, ratio H/L = 2.0. Etymology Yunkai, a regional geographic name in Guangdong Province. Comparison The present new species is distinguished from the genotype, Yunannia gankenensis (gen. et sp. nov) by the narrow ovate shape with a H/L ratio of 2, and the slightly incurved umbo. In contrast to the latter species’ mytiliform shape and a H/L ratio less than 1.5. On the respect of shell shape, the present species is more or less similar to Mytilarca chenmungensis (Conrad) (Pojeta, 1966, pl. 37, figs. 8–18; pl. 38, figs. 1–5, 10), but it differs from the latter species by having a subumbonal edentulous area, a posterior row of taxodont teeth, a large anterior adductor muscle scar, and large anterior pedo-byssal retractors laid on unmbonal septum. Occurrence Gankeng Village, Yunan County, Guangdong Province, Dongchong Formation, Middle Ordovician.
    3  Conodonts and brachiopods from the upper Givetian Renyi Section, eastern Guangxi
    YANG Run-yu YUAN Zhi-wei PENG Zhan HAN Shu-peng YIN Bao-an SHEN Bing SUN Yuan-lin
    2021, 60(3):376-400. DOI: 10.19800/j.cnki.aps.2020036
    [Abstract](518) [HTML](0) [PDF 52.16 M](13787)
    Abstract:
    The Renyi Section is a newly discovered section in the vicinity of Renyi Town, Hezhou City of Guangxi, in which a continuous marine sedimentary succession of the Middle and Upper Devonian is well developed and out-cropped. The succession yields abundant benthic and pelagic fossils. This paper presents a preliminary research resulton the conodonts and brachiopods from the middle part of the Middle-Upper Devonian Baqi Formation (ca. 80 m thick) at this section. Ten species (or subspecies) of three genera of conodonts are recognized from the studied interval, including Polygnathus alatus, P. cf. collieri, P. cristatus, P. dubius, P. dengleri, P. dengleri sagitta, P. webbi, P. xylus, Klapperina disparalvea and Schmidtognathus wittekindti. Seventeen species of 16 genera of brachiopods are also reported herein, including Schizophoria sp., Gypidula sp., productoid gen. et sp. indet., Leiorhynchus kwangsiensis, Coeloterorhynchus sp., Hypothyridina sp., Uncinulus? sp., Fitzroyella sp., “Ypsilorhychus” subellipticus, Desquamatia sp., Spinatrypina douvillii, Spinatrypina sp., Emanuella sp., Mucrospirifer sp., Undispiriferoides tianqipuensis, Cryptonella? sp. and Oligothyrina? sp. According to the distribution of the conodonts, three conodont zones (S. hermanni, P. cristatus and K. disparilis zones) have been recognized from the studied interval, suggesting an age of late Givetian of the Middle Devonian. The brachiopods were mainly collected from two fossiliferous layers near the base and top of the studied interval, representing two different brachiopod assemblages. The brachiopod fauna from the lower fossiliferous layer (ca. 20 cm thick, S. hermanni Zone) is relatively monotonous in composition, mainly consisting of L. kwangsiensis. This finding verifies the Middle Devonian occurrence of the genus Leiorhynchus in South China. The upper fossiliferous layer (ca. 3 m, upper K. disparilis subzone) yields a diverse brachiopod fauna, including at least 15 genera and displaying the highest diversity of brachiopods ever recorded in a single fossiliferous bed from the upper Givetian of South China.
    4  A revision of Mesypochrysa intermedia (Neuroptera: Chrysopidae) and the evolution of Chrysopidae in the Mesozoic
    CHEN Pei-chao WEI Li-xin MAO You-ming SHI Chao-fan WANG Xiao-bing YANG Qiang
    2021, 60(3):401-414. DOI: 10.19800/j.cnki.aps.2021020
    [Abstract](352) [HTML](0) [PDF 6.76 M](2043)
    Abstract:
    The genus Mesypochrysa Martynov, 1927 (Neuroptera: Chrysopidae: Limaiinae) is the oldest genus in the subfamily Limaiinae. The species of this genus can be identified by the numbers of basal subcostal crossveins (0–2), the branches of Rs (7–26), m-cu crossveins (2, 3), the pectinate branches of CuA+MP (4–7), and the pattern of forking of 1A and 2A (forked or not) in the forewing. Mesypochrysa intermedia Panfilov, 1980 is characterized by the presence of one basal subcostal crossvein in the forewing; Rs with about 14 branches; the presence of 1m-cu crossvein; CuA+MP with 6 distal pectinate branches; and 1A, 2A not being forked. Many specimens of this species have been found, but most of them are preserved with only forewings, except one specimen of Mesypochrysa cf. intermedia (NIGP 161886) which has an incomplete hind wing. A new specimen with nearly complete forewings and hind wings of this species was collected from the Middle Jurassic Jiulongshan Formation in Daohugou Village, Ningcheng County, Chifeng City, Inner Mongolia, China. Based on observation of this specimen, we revise the diagnosis of Mesypochrysa intermedia. The recorded specimens of M. intermedia, the differences between the genus Mesypochrysa and other genera of the Mesozoic, as well as the characteristics of each species of Mesypochrysa are also discussed in detail.
    5  New record of petrified wood from the Lower Cretaceous Shahai Formation in Yixian of western Liaoning, Northeast China
    WU Zhen-yu LI Fang-yu TIAN Ning
    2021, 60(3):415-428. DOI: 10.19800/j.cnki.aps.2021002
    [Abstract](489) [HTML](0) [PDF 3.41 M](2183)
    Abstract:
    The western Liaoning region is known as one of the most significant fossil wood localities in China with diverse and abundant Cretaceous petrified woods. The Early Cretaceous petrified wood bearing horizons, including the Yixian, Jiufotang, Shahai and Fuxin formations, are relatively continuous. Among them, the most abundant wood fossils arefound from the Shahai Formation. Though some studies have been carried out previously, the composition of the fossil wood flora of the Shahai Formation remains poorly understood. In this paper, we report some well-preserved fossil woods from the Shahai Formation in Shidonggou village of Yixian County, Liaoning Province. Three species referable to two genera are identified, i.e., Phyllocladoxylon cf. eboracense (Holden) Kr?usel, Xenoxylon conchylianum Fliche and X. watarianum Nishida and Nishida. Among them, Phyllocladoxylon cf. eboracense is anatomically characterized by having distinct growth rings, uniseriate distant radial pits, and one large oopore per cross-field. Xenoxylon watarianum is featured by the presence of distinct growth rings, typical xenoxylean radial pitting, window-like cross-field pits, and a low ray height of 1?10 (mostly 2?5) cells. Then for X. conchylianum, it also bears xenoxylean radial pitting and window-like cross-field pits, but with a higher ray height of 1?21 (mostly 3?10) cells. The current new finding contributes to further understanding of the fossil wood diversity of the Shahai Formation and provides new fossil evidence for revealing the forest composition in western Liaoning during the late Early Cretaceous. The diversity of the Early Cretaceous wood fossils in western Liaoning is summarized. From the perspective of the wood fossils, it is inferred that the forest vegetation may have undergone some degree of changes during the transition of the middle to late Early Cretaceous in western Liaoning. In addition, this paper analyzes the species-level diversity of the Jurassic and Cretaceous Xenoxylon in western Liaoning area, and proposes that this genus was a dominant group all through the late Mesozoic. However, there is a difference in species-level composition between the Jurassic and Cretaceous intervals.
    6  A new species of Osmunda L. (Osmundaceae) from the middle Miocene of Fujian, Southeast China
    WANG Zi-xi SHI Gong-le SUN Bai-nian DONG Chong YIN Su-xin WU Xie-ting
    2021, 60(3):429-438. DOI: 10.19800/j.cnki.aps.2021045
    [Abstract](646) [HTML](0) [PDF 6.70 M](2232)
    Abstract:
    Abundant fossil records indicate that the genus Osmunda L. was widely distributed in the Northern Hemisphere during the Mesozoic and Cenozoic. Here, a new species of Osmunda, namely Osmunda zhangpuensis Z. X. Wang and B N. Sun, sp. nov., is described based on well-preserved sterile pinnules from the middle Miocene Fotan Group in Fujian, Southeast China. The pinnules of the new species are linear-lanceolate with serrate margins and pin-nate venation. Of extant Osmunda species, O. zhangpuensis sp. nov. most closely resembles Osmunda banksiifolia. Thediscovery of the new species suggests that the Osmunda existed in this region during the middle Miocene. Moreover, the presence of O. zhangpuensis sp. nov., together with the epiphyllous fungi on many leaf megafossils of Dipterocarpaceae, Moraceae, Fabaceae, Urticaceae, Calophyllaceae, Euphorbiaceae, and Lauraceae, suggests that the paleoclimate during the middle Miocene in Fujian, China was warm and humid.
    7  Mammutidae from the Yuanmou Basin (southern China) reveal the earlier origin of Sinomastodon
    WANG Shi-qi FU Li-ya JI Xue-ping YANG Xiao-mei JI Yu
    2021, 60(3):439-454. DOI: 10.19800/j.cnki.aps.2020065
    [Abstract](629) [HTML](0) [PDF 2.35 M](2311)
    Abstract:
    This paper reports fossil mammutid proboscideans from the late Miocene of the Xiaohe Formation, Yuanmou Basin, Yunnan Province. They were recovered from three localities: Zhupeng, Huiwoqing, and Leilao, and belong to two taxa: Pliomastodon? zhupengensis comb. nov. and Mammut lufengense. SYSTEMATIC PALEONTOLOGYOrder Proboscidea Illiger, 1811 Family Mammutidae Hay, 1922 Genus Pliomastodon Osborn, 1926 Pliomastodon? zhupengensis (Zhang et al., 1991 in Ji and Zhang, 1997, comb. nov.) Type specimen YICRA YV0787, left M3, see Ji and Zhang (pl. 28, fig. 1). Type locality Zhupeng. Diagnosis Pliomastodon? with moderately elongated symphysis and lower tusks, lacking the posterior mental foramen. Upper tusks straight, dorsally bent and enamel-less. A low degree of cheek teeth zygodonty: relative to Mammut, subdivision of lophs/lophids not pronounced, thick pretrite crescentoids with the possibility of presence of pretrite central conules, interlophs/interlophids half stuffed by pretrite crescentoids and/or central conules. Referred material MCY C1134ZA94, mandible, with associated palate and right upper tusk, from Huwoqing; YMM 297, incomplete mandible, from Leilao; YICRA YV768 and YV784, two left M3s, as well as YMM 3121X081, right m3, from Zhupeng (Figs. 3, 4). Age: Late Miocene, ~8.2?7.2 Ma (Dong and Qi, 2013). Description and comparison The mandibular possesses a straight ventral border. The mandibular symphysis is narrow and moderately elongated with a deep trough. It tips slightly downward. The corpus is strong and the ramus is low. The upper tusk is straight and long. It is slightly dorsally bent without an enamel-band. The lower tusks are short rod-like. They are closely apposed with a nearly round cross-section. The above features are very similar to those of Mammut obliquelophus(Tobien, 1976). The M3 is tetralophodont. The lophs are blunter than those of Mammut. The interlophs are narrow. The pretrite half lophs possess thicker anterior and posterior crescentoids than those of Mammut. Occasionally the pretrite central conules are present. In lateral view from the pretrite side, the crescentoids and/or central conules reach at least half of the interlophs. The posttrite half lophs are less subdivided than those of Mammut. The posttrite main cusp and mesoconelets are generally well-separated. The zygodont crests are blunt. The m2 is trilophodont, and the m3 is tetra- or pentalophodont. The interlophids are wider than the M3, and the posterior pretrite central conules are usually present. Lophids are obliquely arranged with a somewhat chevron in the distal lophids. In some cases, the second pretrite and posttrite half lophids are alternatively positioned. The other features are similar to those of the M3, and differs from the m3 of Mammut in the same way as those of its M3. Pliomastodon? zhupengensis succeeded the low degree of zygodonty from Miomastodon gobiensis of the Middle Miocene of northern China (Wang et al., 2020). Like the other Late Miocene mammutids with high zygodonty, i.e., Mammut and Pliomatodon (Tobien, 1976, Osborn, 1936), Pliomastodon? zhupengensis curved the upper tusks upward and lost the enamel band. The molar morphology of Pliomastodon? zhupengensis displays few differences from Sinamstodon praeintermedius (Figs. 6-A–6-D), except the lower tooth crown and fewer lophids of the m3. It is the potential direct ancestor of the latter, which was recovered from the Shuitangba locality, Zhaotong Basin in the vicinity, ~6.5?6.0 Ma (Wang et al., 2016). Tobien et al. (1986) believed that Sinomastodon is morphologically and phylogenetically close to the American brevirostrinegomphotheres, especially the Notiomastodon, and migrated back from American. This opinion is questioned here: 1, the earliest Notiomastodon occurred at ~2.5 Ma in South America (Mothé et al., 2016), which is far later than the occurrence of Sinomastodon; 2, Sinomastodon sensu Tobien et al. actually comprises two morphological types, a more zygodont-like type (Mastodon intermedius, originally attributed to Mammutidae) from the Pliocene, and a more bunodont-like type from the Pleistocene (originally attributed to Gomphotherium); 3, collagen sequence of Notiomastodon are closer to that of Mammut than of the true elephantids (derived from the gomphotheres) (Buckley et al., 2019), which reveals that the evolution of Gomphotheriidae and Mammutidae was deeply involved rather than simply detached. Sinomastodon is more likely a mammutid. Genus Mammut Blumenbach, 1799 Mammut lufengense (Zhang, 1982) Type specimen YICRA YV0131, left m3, see Zhang (pl. 1, fig. 1). Type locality Shihuiba, Lufeng, Yunnan Province. Referred material YICRA XDYV001, right M2, YICRA XDYV002, anterior two lophs of right M3, YICRA XDYV003, left m2, YICRA XDYV004, left m3, unearthed at the same time from Leilao, Yuanmou, Yunnan Province (Fig. 5). Age: Late Miocene, 6.9?6.2 Ma (Dong and Qi, 2013). Description and comparison The deeply worn M2 and m2 are trilophodont. The M3 (keeping the anterior two lophs) possesses sharp lophs. The posttrite half lophs are subdivided into small conelets with an obscure separation between the main and mesoconelets. The pretrite mesoconelets are short crest-like, and the pretrite crescentoids are thin and sharp, reaching the bottom of the interlophs in side views. The zygodont crest are thin and clear. The m3 is tetralophodont. The lophids are highly mesiodistally compressed with wide interlophids. The posttrite half lophids are moderately to highly subdivided, and the separation between the main and mesoconelets is clearer than that of the M3. The pretrite crescentoids are somewhat thicker than those of the M3, and reach the 1/3 of the interlophid height. Chevron is developed on the posterior two lophids. Generally, the tooth morphology of Mammut lufenense shows little difference from the contemporary Eurasian species, Mammut obliquelophus (= M. preatypicum). Unfortunately, the condition of the upper and lower tusks, and mandibular symphysis is unknown. Here we temporarily keep the species name, ‘lufengensis’, and transferred it to Mammut, as a highly zygodont mammutid representative of southern China during this age. Besides from Yuanmou, Mammut lufenense was also recovered from the adjacent Lufeng (6.9?6.2 Ma) (Dong and Qi, 2013) and Zhaotong (6.5?6.0 Ma) (Ji et al., 2013), Yunnan Province (Figs. 6-E?6-H). It can be inferred that two types of Mammutidae, the less zygodont Pliomastodon?, and the high zygodont Mammut, coexisted in a long period during the late Miocene of southern China.
    8  Pollen analysis of sediments from the foothill of the Purple Mountain in Nanjing
    GE Jing-lian SHU Jun-wu MAO Li-mi
    2021, 60(3):455-470. DOI: 10.19800/j.cnki.aps.2020062
    [Abstract](565) [HTML](0) [PDF 6.91 M](2269)
    Abstract:
    Based on pollen analysis of 17 samples of surface lake sediments from Xuanwu Lake and Qianhu Lake from the foothill of the Purple Moutain in Nanjing, pollen assemblages are established to reveal the relationship between surface pollen flora as well as modern vegetation and to provide a modern reference for Quaternary pollen analysis of lacustrine sediments. The results show that apart from abundant human-induced woody taxa, Pinus and Quercus are the dominant elements in the pollen assemblages, and other important pollen taxa such as Liquidambar, Castanea?Castanopsis?Lithocarpus, Anacardiaceae occur frequently. The pollen spectrum generally indicates the coniferous and mixed evergreen-deciduous broad-leaved forest in the surrounding mountains and hills, consistent with the present vegetation of northern subtropical forest. In addition, herbs such as Poaceae and Artemisia and lake wetland plants such as Hydrocharis and Cyepraceae are abundant. The dominant types of trees from different samples in Xuanwu Lake and Qianhu Lake are highly consistent; each sample is ather stable in contents; and both are little affected by sampling location. By comparing with existing modern pollen data of topsoil in forests in Nanjing area, we found that the pollen assemblages of the surface lake sediments are characterized by stable percentages of dominant taxa with little influences of local habitats, suggesting their advantages of reflecting regional vegetation. In order to improve the representativeness and reliability of the relationship between regional vegetation and pollen assemblages, this paper highly suggests that surface lake sediments should be preferred to use for pollen analysis in Quaternary pollen interpretation. This paper yields new data and provides necessary modern basis for Quaternary palynological investigation in terms of pollen-vegetation relationship in the lower reaches of the Yangtze River, especially in Nanjing area.
    9  Relationship between surface pollen and vegetation on the northern slope of west Tianshan Mountains, China
    YAO Fu-long MA Chun-mei ZHU Cheng YANG Hai-jun
    2021, 60(3):471-482. DOI: 10.19800/j.cnki.aps.2020064
    [Abstract](393) [HTML](0) [PDF 5.20 M](1905)
    Abstract:
    The Tianshan Mountains, one of the famous mountain ranges in northwest China, forms a complete geographic zone and divides Xinjiang province into two different natural geographic units: southern and northern Xinjiang. These two units display distinct vertical gradient distributions of climate, soil and vegetation types which impact on pollen transportation, dispersion, preservation and deposition. Based upon pollen assemblages of 50 modern pollen samples and the data of vegetation plots, both of which were collected from the northern slope of western Tianshan Mountains, we analyzed the relationship between vegetation and surface pollen assemblages and compared different pollen assemblages of the Tianshan Mountains. (1) We divide the pollen spectra into five pollen assemblage zones, i.e., mountain desert, steppe, forest, subalpine meadow, and alpine cushion, according to major vegetation types of the north slope of the western Tianshan Mountains. (2) When the percentage of Picea pollen is 25%–30%, the sample can be considered coming from the Picea forest. The dominance of Picea-Artemisia-Chenopodiaceae-Apiaceae assemblage indicates the existence of a forest vegetation. The subalpine meadow and steppe are dominated by Artemisia-Chenopodiaceae-Poaceae-Picea-Ephedra assemblage. High percentage of Chenopodiaceae-Artemisia pollen indicates mountain desert and alpine cushion vegetation. Picea pollen is representative, and its proportion in a sample is consistent with the distribution of modern vegetation, but is significantly affected by airflow. The distribution of Ephedra pollen is also affected by airflow, and its percentage cannot be used to infer whether the vegetation exists around the sample site or not. Artemisia and Chenopodiaceae pollen are super representative, but they are only of regional ecological significance, while Poaceae pollen shows low representativeness due to its low yield. (3) The vertical pollen spectra are the most complicated in the north slope of western Tianshan.

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