Global Database of Foraminiferal Organic Linings: ForamL Version 1.4

This ForamL Version 1.4 database provides an updated and expanded compilation of references to images of Foraminiferal Organic Linings documented in the extant scientific literature (see Godos et al., 2021, 2024). All organic linings included originate either from recent marine environments or sedimentary rock samples collected on a global scale. The prior review of these sources resulted in a dataset comprising 186 publications, illustrating a total of 821 foraminiferal organic linings. Here, we present an updated version of the ForamL database, which includes 35 additional images that were not published in the ForamL 1.3 (Godos et al., 2024). In total, 856 organic linings have been classified according to supraordinal groups within the phylum Foraminifera (Pawlowski et al., 2013), as well as categorized by fundamental morphological chamber arrangement types. The database is structured into three tables, spanning the entire Phanerozoic, subdivided into Cenozoic, Mesozoic, and Paleozoic erathems/eras, and further devided by systems/periods, including the ;modern period” and older intervals. The “modern period” is an informal, artificial, short temporal category, encompassing foraminiferal organic linings derived from natural settings, including both living and dead material. This category also comprises subfossil remains present in marine sediments that lack full fossilization, representing geologically recent deposits not qualifying as true fossils. For each geological system, referenced scientific publications are organized chronologically. The primary criterion for inclusion in this analysis was the sample preparation methodology, focusing on studies that applied palynological techniques. These involve treating samples initially with hydrochloric acid to dissolve carbonate fractions, followed by hydrofluoric acid to eliminate silicate components. Subsequently, the organic residue was sieved through meshes of 10, 15, or 20 μm to isolate larger organic particles, including palynomorphs containing foraminiferal organic linings, for the preparation of palynological slides. Most studies identified organic residues using optical microscopy, which was often enhanced by analogue or digital imaging. Some researchers employed scanning electron microscopy as a complementary imaging tool. Analysis of the database reveals an increasing trend in the number of documented organic linings from older to younger stratigraphic intervals. The highest frequency of foraminiferal organic linings per 10 million years is observed in the Cenozoic, followed by the Mesozoic, and then the Paleozoic. This pattern extends into the “modern period,” which includes 164 specimens accumulated over the 68 years span represented in the referenced literature. However, this apparent increase reflects a methodological artifact caused by comparing the relatively narrow modern timeframe with the vast scale of geological history.