https://repository.kopri.re.kr/handle/201206/15769 2026-04-08T22:17:01Z 2026-04-08T22:17:01Z Oh, Yeongju Park, Tae-Yoon S. Peel John S. https://repository.kopri.re.kr/handle/201206/16605 2026-02-10T04:22:43Z 2025-12-01T00:00:00Z

Title: Early aculiferan diversification shaped by Ægir-Iapetus palaeogeography: Insights from North Greenland (Cambrian Series 2, Stage 4) Authors: Oh, Yeongju; Park, Tae-Yoon S.; Peel John S. Abstract: Aculifera, comprising Polyplacophora (chitons) and Aplacophora, is one of two major molluscan clades, characterised by a scleritome of mineralised sclerites or plates. Their early evolutionary history is poorly understood due to sparse fossil records bridging possible Terreneuvian (early Cambrian) stem-group taxa and Furongian (late Cambrian) chiton-like articulated representatives. Here, we describe seven species in five genera from the Aftenstjernes & oslash; Formation (Cambrian Series 2, Stage 4) of North Greenland, including a second species, Qaleruaqia bronlundensis sp. nov., of the oldest paleoloricate, Qaleruaqia sp.; the sachitid Hippopharangites groenlandicus, Hippopharangites? sp.; a possible intermediate plate of a chiton-like scleritome, Avannaplax midsommersoensis gen. et sp. nov.; and possible aculiferans Ocruranus? kangerluk and Xianfengella yatesi. Morphological comparisons of the North Greenland assemblage reveal strong affinities with Terreneuvian taxa, including maikhanellids and the Ocruranus-Eohalobia group, supporting their interpretation as stem-group aculiferans. A palaeobiogeographic analysis using 650 global occurrences of Cambro-Ordovician taxa shows that the AE gir Ocean as a principal dispersal corridor for early diversification of aculifera. During the Terreneuvian, aculiferans were widespread along AE gir margins but rare in Laurentia, likely due to isolation by the Iapetus Ocean. From Cambrian Series 2 onward, increased connectivity and expanded low-latitude carbonate platforms fostered diversification in eastern Laurentia, including North Greenland. This assemblage from North Greenland bridges a critical spatio-temporal and morphological gap between the earliest Cambrian taxa and Furongian paleoloricates, offering new insight into aculiferan diversification and palaeobiogeography.

2025-12-01T00:00:00Z Kim, Ji-Hoon Piotr Gasiorek Rho, H. S. Lee, H. Han, S. Kim, J. Kang, Pil-Mo Choi, J. Jung, W. Park, Tae-Yoon S. https://repository.kopri.re.kr/handle/201206/16564 2026-02-09T06:59:11Z 2025-11-01T00:00:00Z

Title: An integrative description of a new species of marine water bear (Heterotardigrada: Echiniscoididae) from the tidal zone of the east coast of Korea Authors: Kim, Ji-Hoon; Piotr Gasiorek; Rho, H. S.; Lee, H.; Han, S.; Kim, J.; Kang, Pil-Mo; Choi, J.; Jung, W.; Park, Tae-Yoon S. Abstract: Tardigrades, or water bears, are microscopic invertebrates renowned for their extraordinary resilience and cryptic diversity. Their microscopic size, paucity of taxonomically distinctive morphological characters, and limited molecular data have caused significant taxonomic deflation. Echiniscoides, the most speciose genus in the family Echiniscoididae, also harbors multiple undescribed species. In this study, we describe a new marine tardigrade species, Echiniscoides testudolapis sp. nov., collected from barnacles inhabiting the intertidal zone of Uljin, Korea. The new species was characterized using an integrative taxonomic approach combining detailed morphological, morphometric, and molecular analyses, including DIC microscopy, SEM microscopy, and molecular phylogenetic reconstructions based on mitochondrial COI sequences. Morphologically, E. testudolapis sp. nov. is distinguished by its dorsal cuticular sculpturing in the form of circular discs with central punctations (weakly elevated processes), the presence of sensory organs on all legs (papilliform on legs I？II, IV, and spike-like on legs III), and a dominant claw formula of 9,9,9,8. Notably, our COI analyses revealed substantial intraspecific genetic variability, with 20 haplotypes identified among 28 individuals (p-distances = 0.1？2.8%). In contrast, the examined nuclear markers exhibited low to no genetic variation (p-distances are 0.05%, 0%, 0.2？0.5%, 0.2？0.4% for 18S, 28S, ITS1, and ITS2, respectively). Single nucleotide polymorphism (SNP) analyses indicated that the observed COI polymorphisms are likely functionally neutral. These findings highlight the value of an integrative taxonomic approach in revealing cryptic diversity and provide new insights into the evolutionary processes and biogeographic patterns shaping marine tardigrades diversity.

2025-11-01T00:00:00Z Myeong, Nu Ri Ryu, Youngil Park, Tae-Yoon S. Jung, Ji Young Jeong, Sujeong Ju, Hyeon Tae So, Yohan Kim, Jinhyun Kim, Mincheol https://repository.kopri.re.kr/handle/201206/16563 2026-02-09T06:54:09Z 2025-09-01T00:00:00Z

Title: Plant species and soil moisture shape rhizosphere microbiota in an unusually productive tundra ecosystem of North Greenland Authors: Myeong, Nu Ri; Ryu, Youngil; Park, Tae-Yoon S.; Jung, Ji Young; Jeong, Sujeong; Ju, Hyeon Tae; So, Yohan; Kim, Jinhyun; Kim, Mincheol Abstract: Background Arctic warming is driving uneven greening across high-latitude regions, leading to the development of unusually productive tundra ecosystems that remain poorly understood. Here, we investigated the soil physicochemical properties and multi-kingdom microbial communities (bacteria, fungi, and micro-eukaryotes) in the rhizosphere of dominant plant species in a highly productive tundra ecosystem in the central part of North Greenland (above 82°N). Results A strong correlation between the normalized difference vegetation index (NDVI) and soil moisture content underscores the critical role of moisture in determining vegetation patterns. Plant species was a key determinant of microbial community structure across all microbial groups, but the strength and nature of these associations varied. Fungal communities were most affected by plant species identity, with distinct associations between mycorrhizal taxa and specific plant species observed in wetter sites. In contrast, bacterial communities were more strongly linked to vegetation-driven changes in soil geochemistry, while micro-eukaryotic communities exhibited comparatively weaker responses to both plant species and soil properties. Additionally, a positive association between nematodes and mushroom-forming fungi (mainly Agaricomycetes) suggests the presence of a functionally interconnected soil food web, and parasitic protists of the Apicomplexan order Eugregarinorida were widespread across most sites, though their ecological roles remain unclear. Conclusions Taken together, our findings suggest a possible role of soil water availability in shaping plant species-specific rhizosphere microbial communities in this highly productive High Arctic tundra ecosystem. Furthermore, the multi-kingdom community data provide a valuable baseline for future research on the ecological functioning and climate sensitivity of increasingly productive Arctic ecosystems.

2025-09-01T00:00:00Z Kim, Ji-Hoon Zawierucha, Krzysztof Rho, Hyun Soo Park, Tae-Yoon S. https://repository.kopri.re.kr/handle/201206/16019 2025-11-05T04:52:23Z 2025-07-01T00:00:00Z

Title: Greenlandic water bears reveal a new morphological trait of external head sensory organs Authors: Kim, Ji-Hoon; Zawierucha, Krzysztof; Rho, Hyun Soo; Park, Tae-Yoon S. Abstract: Tardigrades are microscopic panarthropods renowned for their ability to undergo cryptobiosis. While integrative taxonomy of tardigrades has been intensively applied in the description of tardigrade species over the past two decades, many details of their external morphology remain poorly recognized and under-described. This limitation is largely due to their small size and the limited morphological features useful for classical taxonomy. In particular, compared to heterotardigrades, the external sensory structures of eutardigrades are less studied. In this study, we present a detailed morphological analysis using FE-SEM of two Greenlandic apochelan species, Milnesium grandicupula sp. nov. and M. cf. longiungue. We identified several previously unobserved anatomical structures in milnesiids, including minute sensory structures in the cephalic region. Detailed microphotographs revealed that apochelan tardigrades also possess a set of external sensory structures on the head sensory fields, similar to those observed in other major evolutionary lineages within tardigrades. This finding corroborates the hypothesis of the homology of head sensory organs between eutardigrades and heterotardigrades. Notably, these small sensory structures exhibit a distinctive pattern: a relatively large central organ surrounded by smaller pores, which may be comparable to the sensory dorsal organ (SDO) of crustaceans and the cephalic median organ (CMO) of trilobites.

2025-07-01T00:00:00Z