GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 11-4
Presentation Time: 9:15 AM


LIDGARD, Scott, Integrative Research Center, Field Museum, 1400 S. Lake Shore Dr, Chicago, IL 60605 and MAYER, Paul S., Collections Center, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605-2496,

In a sense, fossil specimens all start as 'problematica,' posing an epistemic problem of parts and wholes. What once-living whole (or evidence of processes) does this part represent, and where does that whole fit into the order of nature? But some specimens achieve great notoriety as designated problematica, defying classification of their represented wholes as to order or class, even phylum or kingdom. Historically, museum collections have played vital roles in resolving part-whole identities—collections are the grist for essential comparative practices, at least most of the time. The labyrinth that is problematica goes back at least to the 18th and 19th centuries, to the beginnings of natural classification, geology, and the flowering of museum studies in Western science. We first identify significant components in resolution of well-known problematica: (1) classification is not static; (2) part-whole relationships often necessitate use of analogy as well as homology; (3) actualistic assumptions are pervasive, in taphonomic studies and in deployment of living 'representatives'; and (4) systematic methods are not static, and the historical turn to phylogenetics has altered the study of problematica in general. We use the recent claim that the Tully Monster is a vertebrate to show how these components and the use of a large museum collection are interrelated in addressing the epistemic problem of a well-known fossil problematicum. The modern practice of digitizing specimens proved essential. Over 4,440 images in low-angle and crossed polarized lighting facilitated searches for new, debated, and rare phylogenetically informative traits among 1,300 mostly fragmentary body fossils. Synchrotron X-ray and SEM analyses helped to tease out preservational features shared with other potentially related fossils groups. The epistemic goals of scientists studying problematica are now broader than ever, not merely seeking identification, but reaching into taphonomy, functional morphology, life cycles and behaviors, sampling biases and the issue of underdetermination in the fossil record, and the integration of morphological and genetic evidence in phylogenetics. Museum collections will play roles in pursuit of these goals.