Uniformity in marine invertebrate ichnology

Abstract

Relationships between ichnology and uniformitarianism are perhaps less complicated than those of their sister subdisciplines, paleontology and paleoecology. Trace fossils are manifestations of benthic behavior; and these traits, although evolving in significant ways, have remained stable over longer spans of time than individual species of invertebrates. The fossil record of behavior in fact originated earlier than the fossil record of invertebrate body parts. Although macroinvertebrates and their traces exhibit tremendous diversity of form and function, these fit into a relatively small number of behavioral patterns. The patterns, in turn, may correlate with prevailing environmental conditions, resulting in gradients among trace fossil assemblages, or ichnofacies. Behavioral patterns and characteristic ichnofacies therefore constitute the main basis for uniformity in ichnology. Thus, the most fundamental questions are: What is the specific function represented by the trace? How will it change as the tracemaker is influenced by other genetic, physiologic, or ecologic stimuli? In which facies will it likely occur? and what preservational biases are apt to modify the fossil record of this behavior and its environmental distribution? Approached from this standpoint, the present is indeed a key to the ichnologic past, and vice versa. In practice, however, the present has been studied considerably less than its importance would dictate.

Probable root structures and associated trace fossils from the Lower Pleistocene calcarenites of Favignana Island, southern Italy: dilemmas of interpretation

“…It is most typ i cal of the Skolithos ichnofacies (Frey and Seilacher, 1980;Pem ber ton et al, 2001), but also oc curs in deeper shelf tempestites (Frey, 1990;Frey and Goldring, 1992).…”

Middle Turonian trace fossils from the Bystrzyca and Długopole sandstones

“…Ophiomorpha is seen most com monly as a shal low-ma rine and mar ginal-ma rine trace fos sil, typ i cal for the Skolithos ichnofacies (Frey and Seilacher, 1980;Pem ber ton et al, 2001), but it oc curs also in an off shore -Cruziana ichnofacies (Frey, 1990;Frey and Howard, 1990). Ophiomorpha should be in terpreted on ichnospecific level be cause some ichnospecies (e.g., Ophiomorpha annulata, O. rudis) are known from deep-sea (Uchman, 1991).…”

“…In shal low-ma rine siliciclastic fa cies only Skolithos and Cruziana Seilacherian ichnofacies (cf. Bromley, 1996) are distin guished (Frey and Seilacher, 1980;. The Skolithos ichnofacies points to de po si tion above the fair weather wave base (i.e.…”

“…Tak ing into ac count the great va ri ety of as well-depositional subenvironments as the trace fos sils as sem blages oc cur ring in shal low-ma rine siliciclastic, the clas sic model of ichnofacies (Seilacher, 1967;Frey and Seilacher, 1980) is of ten in suf fi cient for the de scrip tion of trace fos sil dis tri bu tion (see Uchman and Krenmayr, 2004). Ver ti cal trace fos sils that are abun dant in the Skolithos ichnofacies, oc cur also in the prox i mal and the ar chetypal Cruziana ichnofacies, es pe cially in the storm beds.…”

Firmness Profiles Associated with Tidal-Creek Deposits: The Temporal Significance of Glossifungites Assemblages

“…These are markedly different from the Skolithos ichnofacies that characterize settings with shifting substrates. Frey and Seilacher (1980) restricted the Glossifungites ichnofacies to firmgrounds in marine environments, though the essential components of Seilacher's original (1964) definition remained intact. Working along the Georgia coast, Pemberton and Frey (1985) provided numerous examples of burrowed firmgrounds in a variety of modern settings.…”