Turritellid Research

Why Turritellids are cool!

by Warren D. Allmon

They are one of the most abundant gastropod groups.

Turritelline gastropods (family Turritellidae, subfamily Turritellinae; sensu Marwick, 1957) are common components of many benthic marine assemblages of Early Cretaceous to Recent age worldwide (Allmon, 1988). They are frequently the most abundant macrofossils in assemblages in which they occur, and turritelline-rich assemblages are frequently recognized in the literature (e.g., Scott, 1970, 1974; Squires, 1987; Pan, 1990; Kollmann et al., 2002).

They are extremely diverse.

More than 1500 fossil and Recent species and subspecies have been named (see the database elsewhere on this site). Although it is clear that not all of these are valid, there are also new species being described each year. The group is clearly among the most diverse gastropod clades.

Biostratigraphy

Turritellines are among the most biostratigraphically important molluscan groups for this time interval (e.g., Kauffman, 1977; Saul, 1983; Squires, 1988; Woodring, 1931).

History

Although pre-Cretaceous turritellines are occasionally reported (e.g., Fursich 1984), the oldest confirmed representative of the family is probably early Early Cretaceous (Valanginian): Haustator polonicus Schröder 1995 from Poland (Bandel 1993; Schröder 1995). The type species of the genus Turritella Lamarck 1799 is Turbo terebra Linnaeus 1758.

Turritellid Kitsch (right)

I don't know of any quantitative studies of species frequency in shell arts & crafts, but I'm reasonably sure that turritellids would rank high. I don't know why this is so except that if you want to make long things they are an obvious choice, and of course their inherent aesthetic appeal. My collection has been assembled over the past 20 years or so, mostly from shell shows (the Sanibel-Captiva show in particular), but also from random gift shops as well as through gifts from students and others who learn of my interest. A few have been custom made for me as gifts, including the necktie and the plexiglass obelisk.

Turritella Agate

More Reading on “Turritella” agate

A Bibliography on "Turritella" agate | PDF

Allmon, W.D., 2009, The natural (and not-so-natural) history of “Turritella agate”. Rocks and Minerals, 84(2) (March/April): 160-165. | PDF

Turritellid Species Database

Turritellid Database (v1.6) | Excel

Turritellid Database References | PDF

This database includes all species and subspecies names of which I am aware proposed in the subfamily Turritellinae (sensu Marwick 1957) in Cretaceous and Cenozoic deposits and the Recent, worldwide, and first and last reported stratigraphic occurrences for taxa represented by these names. It thus includes species and subspecies proposed in the 42 "genera" listed in the table below. The dataset contains a total of 1,646 species or subspecies names. The majority of these have not been critically evaluated systematically in recent times and the database makes no attempt to judge validity.

Stratigraphic resolution for these names is at the stage level where possible (approximately 60% of the names used in the analysis), and otherwise at the epoch.

Any attempt to assess species-level Cretaceous and Cenozoic diversity history of turritellines must confront several major challenges (see Allmon 1996 for further discussion). First, the history of systematics in the group goes back about as far as you can go, to the type species of the genus Turritella Lamarck 1799, Turbo terebra Linnaeus 1758, and has been added to by hundreds of workers in numerous languages in varying levels of detail ever since. Second, despite this long history of study, compared to their abundance and geographic and stratigraphic distribution, turritellines are woefully understudied systematically. Some of the most species-rich turritelline faunas (based on published names) have not been studied in a century or more, and we know very little about phylogenetic relationships. Third, we do not know enough about ranges of intraspecific variation in living turritellines, and so we have inadequate data for comparison with fossil species. Finally, stratigraphic resolution is a significant challenge, especially for materials collected and taxa described in the nineteenth century, but also for collections made and species described as recently as 30 years ago. Analysis of Cretaceous species is a particular challenge, because there are likely many still-undescribed species in several areas of the world, including the Western Interior of North America (E. Kaufman, pers. comm.) and central Asia (Allmon, unpublished), among others.

Despite these obstacles, a species-level approach to turritellines as a whole appears to be useful, for at least the following reasons: 1) turritellines are among the most easily recognized of fossil gastropods, which means that they are likely to be described or at least noted when present, even by non-specialists; 2) although turritellines have clearly been the victims of occasionally exuberant over-splitting (e.g., de Gregorio 1890; Sacco 1895; Ellisor 1918), most of which has yet to be cleaned up by modern revision, total diversity of the group as represented by described species names may nevertheless not be seriously overestimated because in almost all faunas that have been studied recently, new species continue to be described even as others are synonymized (e.g., Allison and Adegoke 1969; Dockery 1980; MacNeil and Dockery 1984; Titova 1994a,b; Allmon 1996).

Species described in the following genera and subgenera of the family Turritellidae are included in the dataset.

References

Allmon, W.D. 1988. Ecology of Recent turritelline gastropods (Prosobranchia, Turritellidae): current knowledge and paleontological implications. Palaios, 3: 259-284.

Bandel, K. 1993. Caenogastropoda during Mesozoic times. Scripta Geologica, Special Issue 2:7-56.

Kauffman, E.G. 1977. Evolutionary rates and biostratigraphy. p. 109-142 In E.G. Kauffman and J.E.Hazel (eds.) Concepts and methods of biostratigraphy. Dowden, Hutchinson and Ross, Stroudsburg, PA.

Kollmann, H.A., K. Decker, and D.V. LeMone. 2002. Facies control of Lower Cretaceous gastropod assemblages, southwestern United States, p. 101-146. In R.W. Scott (ed.), Cretaceous Stratigraphy and paleoecology, Texas and Mexico: Perkins Memorial Volume. Gulf Coast Section, SEPM Foundation Special Publication in Geology, no. 1.

Marwick, J. 1957. Generic revision of the Turritellidae. Proceedings of the Malacological Society of London, 32: 144166.

Nützel, A., and K. Bandel. 2000. Goniasmidae and Orthonemidae: two new families of Palaeozoic Caenogastropoda. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 9: 557-569.

Pan, H.-Z. 1990. Late Cretaceous gastropod dominated communities of the western Tarim Basin, southern Xinjiang, China. Lethaia, 23: 273-289.

Saul, L.R. 1983. Turritella zonation across the Cretaceous-Tertiary boundary, California. University of California Publications in Geological Sciences 125: 1-149.

Schröder, M. 1995. Frühontogenetische Schalen Jurrassisicher und Unterkretazischer Gastropoden aus Norddeutschland und Polen. Palaeontographica Abt. A 238: 1-95.

Scott, R.W. 1970. Paleoecology and paleontology of the Lower Cretaceous Kiowa Formation, Kansas. University of Kansas Paleontological Contributions, Art. 52, 94 p.

Scott, R.W. 1974. Bay and shoreface benthic communities in the Lower Cretaceous. Lethaia, 7: 315-330.

Squires, R.L. 1987. Eocene molluscan paleontology of the Whitaker Peak area, Los Angeles and Ventura Counties, California. Natural History Museum of Los Angeles County Contributions in Science, no. 388, 93 p.

Squires, R.L. 1988. Rediscovery of the type locality of Turritella andersoni and its geologic age implications for West Coast Eocene strata, p. 203-208. In M.V. Filewicz and R.L. Squires (eds.), Paleogene stratigraphy, west coast of North America. Pacific Section, SEPM, West Coast Symposium, vol. 58.

Woodring, W.P. 1931. Age of the orbitoid-bearing Eocene limestone and Turritella variata zone of the western Santa Ynez Range, California. Transactions of the San Diego Museum of Natural History 625: 371-388.