Exceptionally preserved caddisfly larval cases (Insecta) from the lower Cretaceous of the Liupanshan basin, Western China

Abstract

Abundant well-preserved tubular fossils of caddisfly (Insecta: Trichoptera) larval cases are reported from the Early Cretaceous Madongshan and Naijiahe formations of the Liupanshan Basin, Ningxia Province, western China. Most cases were mainly preserved in life position and densely packed in various layers. Individual cases in each layer tended to be same in size and were erect and parallel to one another and open at both ends. In a transverse section cut perpendicular to the long axis of the cases, individual case appears to form a rounded ring. Small cases are elliptic in a cross-section oblique to the long axis of the cases. Tube walls are nearly subparallel to one another in longitudinal section with both ends being open. The caudal end of the case slightly tapers and usually points downward. The cases were closely packed, almost touching with one another and lacking bifurcate or connecting structure. The overwhelming majority of cases were partially or fully filled with calcite. The case wall embraces a medium particle layer flanked by inner and outer organic layers. Individual particles are ovate in outline and comprise cryptocrystalline or ganic pellets. SEM imaging shows that those pellets are sub-cylindrical in outline and elliptic in cross section, and are made primarily of calcium carbonate. All features observed justify the assignment of the Liupanshan caddisfly cases to ichnogenus Coprindusia. The extinct insect Ningxiapsyche fangi was found in association with the Liupanshan caddisfly larval cases, and thus could be the candidate of the potential trace-maker.

Invertebrate zoogeomorphology: A review and conceptual framework for rivers

“…The timing of fine sediment transport is also important ecologically because fine sediment is associated with deoxygenation (Ryan, 1991) and the transport of pathogens (Bai & Lung, 2005;Hassard et al, 2016), the effects of which may be more dilute during higher flow events. Therefore, fine sediment released by bioturbation in base flow by zoogeomorphic mechanisms (e.g., by signal crayfish; Rice et al, 2016) may be more damaging than fine sediment entrained during winter floods.…”

“…Invertebrate biostructures, including cases of caddisfly (Figure 4e), can provide a stable spot for calcium carbonate to deposit (Roche et al, 2019), resulting in bioherms (accretionary mounds consisting of fossilized remains surrounded by different geology; Cummings, 1932). In Western China, He et al (2015) recorded caddisfly bioherms 3-5 m high stretching 400-500 m laterally. Similarly, bioherms predominantly composed of layers of caddisfly cases and calcium deposits line the shores of Lake Gosiute, Wyoming, USA (Leggitt & Cushman, 2001).…”

Larval cases of caddisfly (Insecta: Trichoptera) affinity in Early Permian marine environments of Gondwana

“…This may confirm the general evolutionary pathway of the group, as most Recent species occupy freshwater settings. Although some fossil caddisfly cases were reported from deposits indicating saline lake palaeoenvironments 41 42 , only a few species of Recent caddisflies occupy normal-marine waters. These are known only from Australia and New Zealand 43 44 45 46 .…”

Terrestrial records of the Early Cretaceous paleoclimate changes in the Liupanshan Basin, NW China: Evidence from sedimentology and geochemistry

“…The Cretaceous Liupanshan Basin in the northwestern China, situated in the northern mid-latitudes of the North China Block (NCB), contains continues terrestrial uviallacustrine sedimentary record available for the Cretaceous paleoenvironmental reconstructions (Dai et al 2010;Liang et al 2022). The Liupanshan Group contains abundant ora and fauna fossils including Lycoptera, Caddis y, oncolite, and Pseudofrenelopsis He et al 2014;Liang et al 2022) and yield the age of 127 ~ 100 Ma by magnetostratigraphic data (Dai et al 2009). These data could provide high-resolution natural archives of the paleoenvironment and paleoclimate evolution of this terrestrial basin.…”