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Lagerstätten from the Precambrian–Cambrian transition have traditionally been a relatively untapped resource for understanding the paleoecology of the “Cambrian explosion.” This quantitative paleoecological study is based on 10,238 fossil specimens belonging to 100 animal species, 11 phyla, and 15 ecological categories from the lower Cambrian (Series 2, Stage 3) Chengjiang biota (Mafang locality near Haikou, Yunnan Province, China). Fossils were systematically collected within a 2.5-meter-thick sequence divided into ten stratigraphic intervals. Each interval represents an induced time-averaged assemblage of various event (obrution) beds of unknown duration. Overall, the different fossil assemblages are taxonomically and ecologically similar, suggesting the presence of a single community type recurring throughout the Mafang section. The Mafang community is dominated by epibenthic vagile hunters or scavengers, sessile suspension feeders, and infaunal vagile hunters or scavengers represented primarily by arthropods, brachiopods, and priapulids, respectively. Most species have low abundance and low occurrence frequencies, whereas a few species are numerically abundant and occur frequently. Overall, in structure and ecology the Mafang community is comparable to the Middle Cambrian (Series 3, Stage 5) Burgess Shale biota (Walcott Quarry, Yoho National Park, British Columbia, Canada). This suggests that, despite variations in species identity within taxonomic and ecological groups, the structure and ecology of Cambrian Burgess Shale-type communities remained relatively stable until at least the Middle Cambrian (Series 3, Stage 5) in subtidal to relatively deep-water offshore settings in siliciclastic soft-substrate environments.

The early Cambrian Guanshan biota of eastern Yunnan, China, contains exceptionally preserved animals and algae. Most diverse and abundant are the arthropods, of which there are at least 11 species of trilobites represented by numerous specimens. Many trilobite specimens show soft-body preservation via iron oxide pseudomorphs of pyrite replacement. Here we describe digestive structures from two species of trilobite, Palaeolenus lantenoisi and Redlichia mansuyi. Multiple specimens of both species contain the preserved remains of an expanded stomach region (a \"crop\") under the glabella, a structure which has not been observed in trilobites this old, despite numerous examples of trilobite gut traces from other Cambrian Lagerstätten. In addition, at least one specimen of Palaeolenus lantenoisi shows the preservation of an unusual combination of digestive structures: a crop and paired digestive glands along the alimentary tract. This combination of digestive structures has also never been observed in trilobites this old, and is rare in general, with prior evidence of it from one juvenile trilobite specimen from the late Cambrian Orsten fauna of Sweden and possibly one adult trilobite specimen from the Early Ordovician Fezouata Lagerstätte. The variation in the fidelity of preservation of digestive structures within and across different Lagerstätten may be due to variation in the type, quality, and point of digestion of food among specimens in addition to differences in mode of preservation. The presence and combination of these digestive features in the Guanshan trilobites contradicts current models of how the trilobite digestive system was structured and evolved over time. Most notably, the crop is not a derived structure as previously proposed, although it is possible that the relative size of the crop increased over the evolutionary history of the clade.

Photosynthesis is an essential plant biological process. The performance of photosynthesis in grafted plants is affected by either the scion or the rootstock. However, the effect of the scion, rootstock and their interaction in the scion–rootstock combinations on photosynthesis of the grafted trees was not clear. In this research, the photosynthesis was analyzed within 21 citrus scion–rootstock combinations derived from three navel oranges (Citrus sinensis cv. ‘Banfield’, ‘Chislett’ and ‘Powell’) grafted on seven rootstocks [(Swingle citrumelo (C. paradisi × Poncirus trifoliata), Carrizo citrange (C. sinensis × P. trifoliata), X639 (C. reticulata × P. trifoliata), MXT (C. sinensis × P. trifoliata), Hongju (C. reticulata), Ziyang xiangcheng (C. junos) and Trifoliate orange (P. trifoliata)]. Results indicated that photosynthesis of these grafted citrus plants was significantly affected by all the scion, rootstock and their interaction. The rootstock and scion–rootstock interaction had more effect on both chlorophyll fluorescence and photosynthetic parameters with lower p values than the scion. All the scions grafted on Swingle showed the highest electron transport rate at 132.24, 158.39 and 154.59 µmol electrons m−2 s−1, and a higher net CO2 assimilation rate at 11.22, 10.77 and 11.69 µmol m−2 s−1, respectively. The rootstock is the predominant factor affecting the content of photosynthetic pigments, and the combinations using Ziyang xiangcheng as the rootstock had the highest content at 19.83, 20.97 and 20.39 μmol s−1 Kg−1 FW. Electron transport rate is probably the predominant factor determining the final photosynthesis of the grafted citrus trees. This research is the first to reveal the respective effect of the scion, rootstock and their interaction on photosynthesis of citrus scion–rootstock combinations and is valuable in enhancing the understanding of the different performances in citrus scion–rootstock combinations, which aids in selecting optimal scion–rootstock combinations.

Malongitubus kuangshanensis Hu, 2005 from the early Cambrian Chengjiang Lagerstätte of China is redescribed as a pterobranch and provides the best evidence to demonstrate that hemichordates were present as early as Cambrian Stage 3. Interpretation of this taxon as a hemichordate is based on the morphology of the branched colony and the presence of resistant inner threads consistent with the remains of an internal stolon system. The presence of fusellar rings in the colonial tubes cannot be unambiguously proven for Malongitubus, probably due to early decay and later diagenetic replacement of the thin organic material of the tubarium, although weak annulations are still discernible in parts of the tubes. The description of M. kuangshanensis is revised according to new observations of previously reported specimens and recently collected additional new material. Malongitubus appears similar in most features to Dalyia racemata Walcott, 1919 from the Cambrian Stage 5 Burgess Shale, but can be distinguished by the existence of disc-like thickenings at the bases of tubarium branching points in the latter species. Both species occur in rare mass-occurrence layers with preserved fragmentary individuals of different decay stages, with stolon remains preserved as the most durable structures. Benthic pterobranchs may have occurred in some early Cambrian shallow marine communities in dense accumulations and provided firm substrates and shelter for other benthic metazoans as secondary tierers.

A new helminthomorph millipede, Sinosoma luopingense new genus new species, from the Triassic Luoping biota of China, has 39 body segments, metazonites with lateral swellings that bear a pair of posterolateral pits (?insertion pits for spine bases), and sternites that are unfused to the pleurotergites. This millipede shares a number of characters with nematophoran diplopods, but lacks the prominent dorsal suture characteristic of that order. Other “millipede” material from the biota is more problematic. Millipedes are a rare part of the Luoping biota, which is composed mainly of marine and near-shore organisms. Occurrences of fossil millipedes are exceedingly rare in Triassic rocks worldwide, comprising specimens from Europe, Asia, and Africa, and consisting of juliform millipedes and millipedes that are either nematophorans or forms very similar to nematophorans.

A well-preserved fossil priapulid worm, Xiaoheiqingella sp., is reported from the early Cambrian Guanshan Lagerstätte (Cambrian Series II, Stage 4) near Kunming City, Yunnan Province, SW China. The body of the animal consists of four sections: a swollen introvert, a constricted neck, a finely annulated trunk and a caudal appendage. The body configuration exhibits a close resemblance to that of the crown group priapulid Xiaoheiqingella peculiaris from the early Cambrian Chengjiang Lagerstätte. The new discovery provides another striking example of crown group priapulids, representing the third occurrence of crown group fossil priapulids after the Chengjiang Lagerstätte (Cambrian Series II, Stage 3) and the Mazon Creek Lagerstätte (late Moscovian Stage, Pennsylvanian). The discovery also sheds new light on the early diversity and evolution of priapulid worms.

A large collection of macrurous decapod crustaceans is recorded from the middle–late Anisian (Middle Triassic) Guanling Formation in Yunnan Province, China. A remarkable assemblage of over 20,000 vertebrate, invertebrate, and plant fossils collectively referred to as the Luoping Biota has been collected from quarries in the vicinity of the city of Luoping. Among these, arthropods including the decapods are the most common element although articulated fish and reptiles are also common. The decapods represent new taxa, including Koryncheiros luopingensis n. gen. n. sp. within Clytiopsidae, a newly elevated family within Erymoidea; Tridactylastacus sinensis n. gen. n. sp. within Glypheidae; and Yunnanopalinura schrami n. gen. n. sp. within Palinuridae. A single specimen has been referred to Palinuridae sp. Koryncheiros luopingensis exhibits a unique cheliped architecture and the second through fourth chelipeds are subchelate, an extremely rare configuration. Tridactylastacus sinensis also exhibits subchelate closures of pereiopods 2–4, but it bears a distinctive subchelate first pereiopod with an intercalated spine between the fingers on the distal margin of the propodus. Yunnanopalinura schrami represents the oldest occurrence of Palinuridae and Achelata. Collectively, these expand our knowledge of Chinese decapods significantly in that only six species of fossil decapods have been described previously from the country.

Exceptionally preserved carbonate reticulated ridge structures are documented from the lower Middle Triassic Guanling Formation of the Luoping area, eastern Yunnan Province, southwestern China. Macrostructures suggest these reticulated ridge structures are morphologically similar to the growth-related structures in ancient and modern microbial mats. Other such features as minute load structures and pyrite crystals beneath the reticulated layers on bedding surfaces are overlain by a black carbonaceous shale layer. Clay minerals in the reticulated layers are oriented parallel to bedding at the top, and they usually form wavy laminae. These characteristics indicate that these carbonate reticulated ridge structures share a similar microstructure to their siliciclastic analogs, and are also comparable with that of wrinkle structures. SEM imaging shows that many tiny objects—coccoid spheres, rod-like structures and filamentous fibrils—are distinct within those ultra-thin, wavy laminae, suggesting similar accretion and growth models to modern microbial mats. Accordingly, the Luoping reticulated ridge structures are of biogenic origin. These microbial mats are associated with the early Middle Triassic Luoping Biota and they are thought to have played a crucial role in the preservation of the fossils through sealing and microbial coats. An SEM-EDS analysis on fossil fragments and their surrounding matrix reveals that microbial mats also played an important role in the phosphatization of Luoping fossils.

Tiny, pelagic arthropods from the Anisian Luoping Biota exposed in two quarries near Luoping, Yunnan Province, China, represent the numerically most abundant organisms in the assemblage. They form the basis for definition of two, and possibly three, species referred to the order Lophogastrida, family Eucopiidae. Yunnanocopia grandis new genus new species and Y. longicauda n. gen. new species represent the oldest occurrence of mysidaceans in the fossil record. Their anatomy allies them with the Ladinian species Schimperella acanthocercus Taylor, Schram, and Shen, 2001, from Guizhou Province, China, which previously was thought to be the oldest lophogastrid, and with extant species of Eucopiidae. Their appearance in the Anisian represents one additional element of the early faunal radiation within the Luoping Biota following the end-Permian extinction event. Presence of well-preserved oostegites, along with other morphological features, documents a conservative bauplan expressed in Eucopiidae.

Detailed sedimentological and quantitative taphonomical analyses of 11,974 fossil specimens from an early Cambrian (Stage 3) Chengjiang-type deposit near Haikou, Yunnan, reveals significant relationships between the original depositional environments and the composition and preservation of their respective fossil assemblages. In general, the Maotianshan Shale is characterized by superimposed couplets of laminated background and thin event mudstone layers representing two distinct taphofacies, A and B, respectively. Fossils in taphofacies A consist predominantly of indeterminate organic elements and fecal or algal strings with few, poorly preserved, soft-bodied animals. Among those, disarticulated arthropods account for 84.3% of specimens (mostly isolated valves of Kunmingella douvillei) and 51.4% of species. Poriferans represent 7.4% of specimens and 22.9% of species. Fossils in this taphofacies have undergone significant pre- or syn-burial decay and represent limited time-averaged assemblages exhibiting low species richness. By contrast, taphofacies B contains greater numbers of species and specimens and better preserved soft-bodied animals. Taphofacies B represents mostly smothered organisms by distal tempestites. Arthropods are also dominant in taphofacies B, both in terms of species richness (41%) and abundance of specimens (44%). Poriferans, priapulids, lobopods, and brachiopods exhibit similar low species richness (6–8% each), but poriferans and lobopods are numerically rare, at around 1% each, whereas priapulids and brachiopods make up 26% and 24% of specimens, respectively. The arthropod Kunmingella douvillei (19%), the priapulid Cricocosmia jinningensis (19%), and the brachiopod Diandongia pista (18%) are the most abundant species in taphofacies B. Fossil assemblages in taphofacies A and B have similar recurrent and abundant species and similar temporal trends in evenness and richness, but taphofacies A captures only a portion of the species that are preserved in taphofacies B. These results suggest that the fossil assemblages present in both taphofacies represent a single local community subjected to two different taphonomic processes and imply similar recurrent environmental conditions within the section studied.