A unique Late Cretaceous fossil wood assemblage from Chilean Patagonia provides clues to high-latitude continental environment

Fossil plants, including large trunks, stems, some branches, and twigs, were collected from the Maastrichtian (68.9 Mya), upper Dorotea Formation in the Magallanes/Austral Basin, 16 km north of the Cerro Guido-Las Chinas complex in the southern Chilean Magallanes region. These fossil trunks range from 0.2 m to 2.2 m in length. Petrographic slides were made in three sections (transverse, radial, and tangential) and analysed under a light microscope to study the permineralised fossils. The woods and stems belong to Austroginkgoxylon gen. et sp. nov., Agathoxylon antarcticum, Podocarpoxylon paradoxi sp. nov., Podocarpoxylon mazzonii, Palmoxylon subantarcticae, and Nothomalvaceoxylon magallanense gen.et sp. nov. The growth rings of gymnosperms and anatomical characters of angiosperms were analysed to obtain palaeoecological data. Interactions between gymnosperm roots growing into the secondary xylem of an angiosperm (nurse logs) are recorded. The data obtained from the fossil woods suggest ..., The fossil woods described here are based on observations of 12 logs of silicified woods and stems collected from 16 km to the north of the Cerro Guido locality, Magallanes region, southern Chile (Fig. 1). Observations and descriptions of the slides were carried out with light microscopic (LM). Slides of the cross (CS), radial (RS), and tangential (TS) wood sections were prepared for observation using a Nikon light microscope. The terminology used follows, in general, the IAWA list of microscopic features (IAWA 2004, 1989). Cell dimensions are based on a minimum of 25 measurements, and the numbers in brackets indicate the minimum and maximum values. Two indices were used to quantify the intertracheary pitting: the ‘Contiguity percentage index (Cp) and Seriation index (Si)’ of Pujana et al. (2016). Values of Si equal to or close to 1.00 indicate that all the intertracheary pits are uniseriate, while values of Si >1.00 indicate two or more seriate pits. Values of Cp equal to or close..., Libre Office. Version: 7.3.6.2 (x64) / LibreOffice Community Past 4.03. Paleontological stadistics software for education and data analysis., ### DATA SET INCLUDE 7 (seven) files 1. Coexistence Approach method.ods 2. Mean Sensitivy.ods 3. CSDM CURVE CPAP 7192.ods 4. CSDM CURVE CPAP 7193.ods 5. CSDM CURVE CPAP 7194.ods 6. CSDM CURVE CPAP 7195.ods 7. CSDM CURVE CPAP 7196.ods. **COEXISTENCE APPROACH METHOD** Author/Principal Investigator Information: Leandro C. A. Martnez Co-Investigator Information: Juan Pablo Pino M. Name: Juan Pablo Pino M. ORCID: . Institution 1: Laboratorio de Paleoecologa, Facultad de Ciencias, Universidad de Chile. Address 1: Las Palmeras 3425, uoa, Santiago, Chile. Institution 2: Laboratorio de Paleobiologa de Antrtica y Patagonia, Instituto Antrtico Chileno. Address 2: Lautaro Navarro 1245, Punta Arenas Chile Email: Date of data collection: 2023-20-05 Geographic location of data collection: El Puesto. Las Chinass River Valley, Magallanes Region, Chile. Information about funding sources that supported the collection of the data: The fossil woods and thin sections are stored in the Pale...本研究的化石植物标本（包含大型树干、茎干、部分枝条与细枝）采集自智利南部麦哲伦地区Cerro Guido-Las Chinas综合体以北16公里处的麦哲伦/澳大利亚盆地马斯特里赫特阶（6890万年前）的多罗特阿组上段。这些化石树干的长度介于0.2米至2.2米之间。 研究人员制作了横切面、径向切面与切向切面三类岩石薄片，通过光学显微镜（Light Microscope，LM）对矿化化石开展分析。 本次研究的木材与茎干标本分别隶属于：澳银杏木属（Austroginkgoxylon）新属新种、南极南洋杉型木（Agathoxylon antarcticum）、悖论罗汉松型木（Podocarpoxylon paradoxi）新种、马佐尼罗汉松型木（Podocarpoxylon mazzonii）、亚南极棕榈木（Palmoxylon subantarcticae）以及麦哲伦假锦葵木属（Nothomalvaceoxylon magallanense）新属新种。 研究通过分析裸子植物的生长轮与被子植物的解剖特征获取古生态学数据；同时记录了裸子植物根系侵入被子植物次生木质部（即保育木（nurse logs））的相互作用现象。从该化石木材中获取的数据表明…… 本研究描述的化石木材基于对智利南部麦哲伦地区Cerro Guido遗址以北16公里处采集的12件硅化木材与茎干标本的观测（图1）。薄片的观测与描述均通过光学显微镜完成，研究使用尼康光学显微镜对横切面（CS）、径向切面（RS）与切向切面（TS）的木材薄片进行观测。 本研究采用的术语总体遵循国际木材解剖学家协会（IAWA）的微观特征列表（IAWA 2004, 1989）。细胞尺寸基于至少25次测量结果，括号内的数值分别表示最小值与最大值。 本研究采用两个指数量化管胞间纹孔：即Pujana等人（2016）提出的毗邻度百分比指数（Cp）与序列性指数（Si）。当Si等于或接近1.00时，表明所有管胞间纹孔均为单列；当Si>1.00时，表明存在两列及以上的纹孔。Cp等于或接近…… 本研究使用的软件包括Libre Office 7.3.6.2（x64）社区版，以及用于教学与数据分析的古生物统计软件PAST 4.03。 ### 本数据集包含7个文件： 1. 共存分析法（Coexistence Approach method）.ods 2. 平均灵敏度（Mean Sensitivity）.ods 3. CSDM曲线CPAP 7192.ods 4. CSDM曲线CPAP 7193.ods 5. CSDM曲线CPAP 7194.ods 6. CSDM曲线CPAP 7195.ods 7. CSDM曲线CPAP 7196.ods **共存分析法** 作者/首席研究员信息：莱昂德罗·C·A·马丁内斯（Leandro C. A. Martínez） 共同研究员信息：胡安·巴勃罗·皮诺·M.（Juan Pablo Pino M.） 姓名：胡安·巴勃罗·皮诺·M. ORCID号：无 机构1：智利大学理学院古生态学实验室 地址1：智利圣地亚哥Las Palmeras 3425号 机构2：智利南极研究所南极与巴塔哥尼亚古生物学实验室 地址2：智利蓬塔阿雷纳斯Lautaro Navarro 1245号 电子邮箱：无 数据采集日期：2023年5月20日 数据采集地理区域：智利麦哲伦地区El Puesto，拉斯奇纳斯河谷 资助信息：该化石木材与薄片标本保存于古……