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...