Biodiversity of ecosystems in an arid setting: The late Albian plant communities and associated biota from eastern Iberia

Palynology Ninety-two samples have been collected in the three cropping out successions described above (Fig 1). Although sampling primarily focused on amber-bearing strata, all suitable levels of the sections were carefully sampled (Figs 3–5) in order to obtain a more accurate and continuous biostratigraphic framework. The three logged sections were drawn using the software SedLog [66] in combination with Adobe Illustrator (www.adobe.com). A total of 15 rock samples from the San Just, 36 from the Cortes de Arenoso and 41 from the Arroyo de la Pascueta sections were prepared for palynological analysis. Palynological resi- dues were processed using acid digestion with HCl and HF at high temperatures [67, 68]. When required, a short oxidation with HNO3 (“nitric wash”) was performed in some residues. The residues were then concentrated by sieving through 500, 250 and 10 μm sieves, mounted Fig 5. Stratigraphic log of the upper Albian/lower Cenomanian Cortes de Arenoso section (CA), showing the distribution of selected biostratigraphically relevant miospores (see the legend in Fig 3). The La Hoya amber outcrop is at the top of the section (level 35). Red dots: location of the collected samples. Black dots: stratigraphic distribution of the selected taxa. Ø: barren samples. https://doi.org/10.1371/journal.pone.0282178.g005 PLOS ONE Late Albian desert biota from Iberia PLOS ONE | https://doi.org/10.1371/journal.pone.0282178 March 2, 2023 8 / 51