Geobios最新文献 - Book学术

A new macroflora from the Turonian–Coniacian Moreno Hill Formation, New Mexico, USA 美国新墨西哥州Turonian-Coniacian Moreno Hill组一个新的大型植物区系

IF 1.5 4区地球科学

Geobios Pub Date : 2026-08-01 Epub Date: 2026-06-11 DOI: 10.1016/j.geobios.2026.04.002

Charl D. Cilliers, Dori L. Contreras, Ryan T. Tucker, Alakendra N. Roychoudhury, Lindsay E. Zanno

{"title":"A new macroflora from the Turonian–Coniacian Moreno Hill Formation, New Mexico, USA","authors":"Charl D. Cilliers, Dori L. Contreras, Ryan T. Tucker, Alakendra N. Roychoudhury, Lindsay E. Zanno","doi":"10.1016/j.geobios.2026.04.002","DOIUrl":"10.1016/j.geobios.2026.04.002","url":null,"abstract":"<div><div>The Moreno Hill Formation of the Salt Lake Coal Field (New Mexico, USA) preserves terrigenous sediments deposited from ∼90.9 until after 88.6 Ma, a critical window of climatic recovery following the ∼94.5 Ma peak of the Cretaceous Thermal Maximum. Recent fieldwork uncovered new macrofloral assemblages: a lower member flora derived from a paralic delta plain, with carbonaceous, pedogenetically altered floodplain sediments indicating often waterlogged conditions, and an upper member flora uncovered from slightly drier, more distal floodplain sediments. We report 18 distinct foliar morphotypes from the study of 116 leaf specimens. Dicot angiosperms are the most diverse in both assemblages, including platanoids, <em>Saliciphyllum</em>, and <em>Cinnamomoides</em>. While only two dicot morphotypes are shared between the lower and upper assemblages, two conifers (<em>Brachyphyllum</em> and taxodiaceous Cupressaceae indet.) are found in both. The fossils at both sites were collected from overbank deposits and lack evidence for significant transport; thus, we infer that the floodplains adjacent to channels during this interval were occupied by a mixed angiosperm-conifer woodland ecosystem. Although the two assemblages are separated by ∼1.5 to 2 million years, they reflect similar floodplain woodlands on a changing landscape in which the Western Interior Seaway was regressing and the local conditions drying. Sedimentological, leaf physiognomic, and wood growth-ring data collectively support persistent warm, yet gradually more seasonal conditions after the thermal maximum. This first report of Moreno Hill Formation leaf macrofossils establishes a regional Turonian–Coniacian palaeobotanical baseline for future studies of vegetation and ecosystem change in the southern Western Interior.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"97 ","pages":"Pages 13-33"},"PeriodicalIF":1.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148652056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biomarker signatures in Eocene amber: Insights into chemotaxonomy at the genus level 始新世琥珀的生物标志物特征：属水平上的化学分类学见解

IF 1.5 4区地球科学

Geobios Pub Date : 2026-08-01 Epub Date: 2026-05-07 DOI: 10.1016/j.geobios.2026.04.001

Tanu Priya, Suryendu Dutta, Yengkhom Raghumani Singh, Kishore Kumar Thapa

{"title":"Biomarker signatures in Eocene amber: Insights into chemotaxonomy at the genus level","authors":"Tanu Priya, Suryendu Dutta, Yengkhom Raghumani Singh, Kishore Kumar Thapa","doi":"10.1016/j.geobios.2026.04.001","DOIUrl":"10.1016/j.geobios.2026.04.001","url":null,"abstract":"<div><div>Fossil resin preserves molecular information that provides valuable insights into the composition of palaeovegetation and its palaeoclimatic significance. Variation in the chemistry of fossil resin derived from different plants serves as an important tool for understanding plant chemotaxonomy. However, most previous studies have limited the chemotaxonomic interpretation of fossil resins to the family level. In this study, we present a detailed molecular signature of Eocene amber from North-East India to determine its botanical source at the genus level to understand the nature of Eocene forests in the area. Gas chromatography-mass spectrometry (GC-MS) analyses reveal the presence of C<sub>15</sub> sesquiterpenoids along with C<sub>30</sub> pentacyclic triterpenoids in the total ion chromatograms (TICs), indicating an angiosperm origin of the fossil resin. The presence of dammarane compounds in the fossilised resin suggests they originate from the Dipterocarpaceae family. Modern resin from two different genera of Dipterocarpaceae, <em>Shorea</em> and <em>Dipterocarpus</em>, are also studied in parallel to reconstruct the botanical source of the fossil resin. The resin from <em>Shorea</em> is mainly composed of β-amyrin and amyrone compounds, while the resin from <em>Dipterocarpus</em> mainly contains dipterocarpol and other dammarane triterpenoids. The fossil resin is rich in ocotillone, dipterocarpol, 20, 24-epoxy-25-hydroxy-dammaran-3-one, and oxidised dammarane derivatives, and lacks amyrin-type triterpenoids, aligning with the molecular signature of modern <em>Dipterocarpus</em>. Therefore, these findings suggest that the amber was produced by <em>Dipterocarpus</em> trees and provide direct biomolecular evidence for the presence of dipterocarp-dominated, humid tropical rainforest elements in North-East India during the Eocene.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"97 ","pages":"Pages 53-61"},"PeriodicalIF":1.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148652100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biostratigraphic evidence for Oligocene-Miocene and Oligocene-Pliocene unconformities, onshore Sarawak, Malaysia and their regional implications 马来西亚沙捞越海岸渐新世-中新世和渐新世-上新世不整合的生物地层证据及其区域意义

IF 1.5 4区地球科学

Geobios Pub Date : 2026-08-01 Epub Date: 2026-05-19 DOI: 10.1016/j.geobios.2026.05.002

Soon Mun Chin, Meor Hakif Amir Hassan, Stephen Noon, Mazlan Madon, Arindam Chakraborty

{"title":"Biostratigraphic evidence for Oligocene-Miocene and Oligocene-Pliocene unconformities, onshore Sarawak, Malaysia and their regional implications","authors":"Soon Mun Chin, Meor Hakif Amir Hassan, Stephen Noon, Mazlan Madon, Arindam Chakraborty","doi":"10.1016/j.geobios.2026.05.002","DOIUrl":"10.1016/j.geobios.2026.05.002","url":null,"abstract":"<div><div>This study presents biostratigraphic and sedimentological insights from six newly documented and two legacy described outcrops from the Tinjar Province of Central Sarawak, Malaysia. Palynological analysis identified four local palynomorph assemblage zones: FT-I (Late Oligocene), FT-III (Early Miocene), SP-I (Late Miocene–Pliocene) and SP-II (Late Pliocene). The Nyalau Formation contains the FT-I and FT-III zones, while strata containing SP-I and SP-II zones are part of an unnamed unit that is age-equivalent to the Liang Formation. Two unconformities were identified in the studied sections: (<em>i</em>) an angular unconformity separating upper Oligocene from Lower Miocene strata in the Nyalau Formation with an approximately 2 Myr age gap correlated with the Base Miocene Unconformity of the offshore Sarawak Basin; and (<em>ii</em>) an unconformity between the upper Oligocene Nyalau Formation and the Pliocene Liang Formation-equivalent strata; this unconformity represents a hiatus of approximately 19 Myr correlated with the offshore Base Cycle VI Unconformity and is linked to a widespread uplift event in NW Borneo during the Miocene. The sediments were deposited in the supratidal to intertidal zone of a marginal marine setting, in proximity to fluvio-deltaic sources and influenced by periodic marine transgressive events. Sedimentological records revealed four facies successions: (<em>i</em>) tide-dominated delta; (<em>ii</em>) estuarine bay; (<em>iii</em>) wave-dominated shoreface; and (<em>iv</em>) fluvio-tidal channel. Palynological data suggest a predominantly warm-wet, humid climate with intermittent seasonal conditions for the Late Oligocene, Early Miocene and Late Miocene–Pliocene.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"97 ","pages":"Pages 35-51"},"PeriodicalIF":1.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148652055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fossil leaves of Pandanaceae from India suggest Paleogene persistence of the family in South Asia 来自印度的熊猫科树叶化石表明该科在南亚的古近纪持续存在

IF 1.5 4区地球科学

Geobios Pub Date : 2026-08-01 Epub Date: 2026-05-18 DOI: 10.1016/j.geobios.2026.05.001

Harshita Bhatia, Gaurav Srivastava

{"title":"Fossil leaves of Pandanaceae from India suggest Paleogene persistence of the family in South Asia","authors":"Harshita Bhatia, Gaurav Srivastava","doi":"10.1016/j.geobios.2026.05.001","DOIUrl":"10.1016/j.geobios.2026.05.001","url":null,"abstract":"<div><div>Pandanaceae (the screw-pine family) represents an early-diverging monocot lineage with a predominantly paleotropical distribution, yet its fossil record remains sparse and uneven, particularly in South Asia. Here, we report well-preserved fossil leaves attributable to <em>Pandanites trinervis</em> (Ettingsh.) J. Kvaček et A.B. Herman, from the late Oligocene Tikak Parbat Formation of the Makum Coalfield, Assam, India. The fossils are characterized by elongate linear laminae having a distinctive M-shaped transverse section with midvein (1°), uniformly developed 2° parallel veins of the same width, transverse veins (3°) obliquely to perpendicularly oriented, and well-developed marginal prickles, a combination of characters diagnostic of Pandanaceae. This record constitutes macrofossil evidence of pandanaceous leaves from the Indian Paleogene and bridges a critical temporal and geographic gap between Late Cretaceous Laurasian occurrences and younger Cenozoic tropical records of the family. The Makum fossils suggest Paleogene persistence and ecological continuity of Pandanaceae across the paleotropics prior to their Neogene diversification and temporally coinciding with molecularly inferred diversification of extant <em>Pandanus</em> lineages in the late Eocene–Oligocene. Sedimentological, palynological, and CLAMP-based paleoclimatic data indicate deposition in warm, humid, lowland deltaic environments dominated by freshwater swamps, riparian corridors, and evergreen forests, closely matching the ecological preferences of extant Pandanaceae. These findings underpin the role of the Indian subcontinent as an important region of persistence for pandanaceous lineages during the Paleogene and provide new insights into the biogeographic history of the family in tropical Asia.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"97 ","pages":"Pages 1-11"},"PeriodicalIF":1.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148652057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A histological approach to investigate the decay of gastropod internal organs 腹足动物内脏腐烂的组织学研究

IF 1.6 4区地球科学

Geobios Pub Date : 2026-06-01 Epub Date: 2026-02-18 DOI: 10.1016/j.geobios.2026.02.001

Nora Corthésy , Christian Klug , Allison C. Daley , Farid Saleh

{"title":"A histological approach to investigate the decay of gastropod internal organs","authors":"Nora Corthésy , Christian Klug , Allison C. Daley , Farid Saleh","doi":"10.1016/j.geobios.2026.02.001","DOIUrl":"10.1016/j.geobios.2026.02.001","url":null,"abstract":"<div><div>Molluscs are important components in both past and modern ecosystems. Understanding their evolutionary history relies on accurately interpreting their past morphologies as preserved in the fossil record. However, organisms typically undergo decay before geological processes intervene to stabilise parts of their anatomy as fossils. To assess the impact of decay on our understanding of ancient morphologies, decay experiments have been conducted in controlled laboratory settings. Such experiments have rarely been applied to gastropods, as their mineralised shell covers internal organs, making direct observation of decaying anatomies experimentally challenging. Here, we conducted decay experiments on 55 snails over 10 days, using histological sections to observe internal morphological changes over time. Our results show that most of the organs we monitored decay uniformly, except for the hepatopancreas, which decomposes more slowly than the rest. Importantly, decay proceeded faster on the outside than on the inside of the hepatopancreas, suggesting that digestive enzymes of microbiota in gastropods may not be as efficient at tissue degradation as those in the digestive systems of other bilaterians.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"95 ","pages":"Pages 13-22"},"PeriodicalIF":1.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148153697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Re-examination of Pulchrilamina Toomey and Ham, 1967 from Lower Ordovician strata of Laurentia Laurentia下奥陶统地层Pulchrilamina Toomey和Ham， 1967的再检验

IF 1.6 4区地球科学

Geobios Pub Date : 2026-06-01 Epub Date: 2026-02-25 DOI: 10.1016/j.geobios.2026.02.002

Juwan Jeon , Qi-Jian Li , Natsuko Adachi

{"title":"Re-examination of Pulchrilamina Toomey and Ham, 1967 from Lower Ordovician strata of Laurentia","authors":"Juwan Jeon , Qi-Jian Li , Natsuko Adachi","doi":"10.1016/j.geobios.2026.02.002","DOIUrl":"10.1016/j.geobios.2026.02.002","url":null,"abstract":"<div><div>The Early Ordovician saw a transition in reef type from microbial-dominated buildups to gradually increasing skeletal frameworks, expressed as regionally heterogeneous constructional pathways. Among these early reef builders, <em>Pulchrilamina</em> <span><span>Toomey and Ham (1967)</span></span> has long been regarded as a problematic laminar reef-builder of uncertain affinity. The genus was initially reported from Laurentia and has subsequently been recognized elsewhere only from South China. Here, we re-examine the type material of <em>Pulchrilamina</em>. The skeleton is composed of stacked laminar sheets alternating with sediment, internally composed of long, slender, spinose rod-like elements that are variably spaced, locally inclined, and protrude both downwards beneath the basal growth surface and upwards beyond the uppermost lamina into overlying sediment. These elements are weakly integrated with locally preserved cyst plate-like fabrics. Their morphology and mode of development differ from the pillar architectures that are characteristic of labechiid stromatoporoids, supporting the interpretation of the structures as spicular elements rather than as pillars of stromatoporoid-grade skeletal elements. Together, these features indicate that <em>Pulchrilamina</em> may record an intermediate skeletal grade between constructional organizations dominated by cyst plates and skeletal architectures characterized by spicular elements, and requires further examination using better-preserved material and additional valid taxa attributed to pulchrilaminids. The emergence of <em>Pulchrilamina</em> broadly coincided with the appearance of calcified reef-associated organisms, including stromatoporoids and bryozoans. These patterns support the interpretation that early skeletal reef ecosystems developed through multiple, regionally restricted constructional pathways that reflect an early phase of experimentation in hypercalcified skeletal construction among sponges.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"95 ","pages":"Pages 23-32"},"PeriodicalIF":1.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148153698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

IF 1.6 4区地球科学

Geobios Pub Date : 2026-06-01 Epub Date: 2026-03-21 DOI: 10.1016/j.geobios.2026.02.004

Antonella Cinzia Marra

引用次数: 0

Evidence of spondylosis deformans in an adult individual of the extinct Scelidotheriid sloth Catonyx cuvieri (Lund, 1839) from the Late Pleistocene of the Brazilian Intertropical Region 巴西热带地区晚更新世已灭绝的棘齿目树懒Catonyx cuvieri （Lund, 1839）成年个体脊椎畸形的证据

IF 1.6 4区地球科学

Geobios Pub Date : 2026-06-01 Epub Date: 2026-03-12 DOI: 10.1016/j.geobios.2026.02.005

Gabriela Alves Lage , Dayana Ellen Miranda Dias , Luciano Artemio Leal , Mário André Trindade Dantas

引用次数: 0

First discovery of the Frasnian–Famennian (F–F) boundary with black shale deposition in the Carnic Alps, Italy 意大利卡尔尼阿尔卑斯山脉首次发现弗拉斯-法门尼亚（F-F）界黑色页岩沉积

IF 1.6 4区地球科学

Geobios Pub Date : 2026-06-01 Epub Date: 2025-12-27 DOI: 10.1016/j.geobios.2025.12.002

Xiaoyu Jin , Carlo Corradini , Maria G. Corriga , Claudia Spalletta

引用次数: 0

First authentic fossil evidence of a great duckweed (Araceae: Lemnoideae) from the Eocene of India 来自印度始新世的大浮萍（天南星科：浮萍科）的第一个真实的化石证据

IF 1.6 4区地球科学

Geobios Pub Date : 2026-06-01 Epub Date: 2026-02-25 DOI: 10.1016/j.geobios.2026.02.003

Ashif Ali , Rafael Felipe de Almeida , Raman Patel , Rajendra Singh Rana , Mahasin Ali Khan

{"title":"First authentic fossil evidence of a great duckweed (Araceae: Lemnoideae) from the Eocene of India","authors":"Ashif Ali , Rafael Felipe de Almeida , Raman Patel , Rajendra Singh Rana , Mahasin Ali Khan","doi":"10.1016/j.geobios.2026.02.003","DOIUrl":"10.1016/j.geobios.2026.02.003","url":null,"abstract":"<div><div><em>Spirodela</em> Schleid. is one of the most abundant and widespread giant duckweeds (Araceae: Lemnoideae), although its fossil record remains relatively unexplored. We present a well-preserved, impressed and compressed fossil rosette bearing four leaves similar to this extant free-floating great duckweed from the early Eocene (Palana Formation) sedimentary sequences of Gurha Lignite Mine, Rajasthan, western India. We infer its taxonomic position based on phylogenetic analysis using macromorphological traits and compare it with other modern and fossil species of Lemnoideae. The fossil specimen is characterized by four peltate sessile leaves (one mother, two daughters, and one granddaughter) arranged spirally in a rosette, leaves with campylodromous venation, and the presence of stolons and adventitious roots. After a thorough comparison, we described our Eocene specimen as a new genus and species, namely <em>Eospirodela indica</em> Ali, Almeida et Khan gen. et sp. nov. Together with other fossils reviewed from the literature, this new taxon helps to elucidate the evolution of duckweeds. Our finding strongly supports the existence of a freshwater ecosystem complementing the earlier published data on the Rajasthan Basin during the early Eocene (55 ± 10 Ma), in contrast to the present desert vegetation of the region. It also throws light on the paleoecological and paleobiogeographical history of duckweeds.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"95 ","pages":"Pages 1-11"},"PeriodicalIF":1.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148153696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0