Ichnotaxonomy: Finding Patterns in a Welter of Information - Trace Fossils as Indicators of Sedimentary Environments - page 60

and Bertling et al. (2006) to understand how the rules have evolved in recent
decades and how they apply to trace fossils today.
One aspect of the Code that is especially troubling to newcomers is the fact
that many rules incorporate cut-off dates. Taxa named before January 1, 1931
could be based on an illustration without a diagnosis; taxa named on or after that
date cannot. Before 2000, ichnogenera could be named without designating a
type ichnospecies; thenceforward, they must have a type ichnospecies. And
so on. Anyone can learn the complexities of the Code with practice, though
for most non-specialists the time could be better spent in cultivating a system-
atist as coauthor. Take a taxonomist out to dinner!
7.2 A Brief History of Ichnotaxonomy
A little history will go a long way toward understanding the current status of
ichnotaxonomy. In the early years, trace fossils were either mostly misidenti-
fied as plants and named as such (e.g., modern Fucus, ancient Fucoides
Brongniart, 1823 ), or correctly identified as the burrows, trackways, and so
on of animals. Where a maker could be inferred, their trace fossils tended
to be named as ancient examples of them (e.g., Arenicolites Salter, 1857 for
supposed maker Arenicola ). Where the maker was unknown, the trace was
often treated as evidence of the animal, and the unknown animal could be
named on this basis (e.g., trackway Chirotherium Kaup, 1835 , the name mean-
ing “hand animal”; burrow Histioderma Kinahan, 1858 , not merely attributed
to worms but regarded as one in its own right). When an enterprising entomolo-
gist extended this line of reasoning to modern gall wasps, using the structure of
plant galls as evidence of otherwise unknown species of wasps, the taxonomic
community, predominated by entomologists, reacted in 1964 by banning all
names for “the work of animals” that were established after a cut-off date
of December 31, 1930.
Paleontologists who worked with trace fossils were inconvenienced by this
turn of events, because names of trace fossils that were established in 1930 or
earlier were protected by the ICZN and names erected afterward were not. The
result was a broad range of proposals on how to classify trace fossils inside or
outside the Code , which we need not examine here, as most of these proposals
did not take hold ( H¨ntzschel and Kraus, 1972 ). H¨ntzschel and Kraus, and later
Bromley and F¨rsich (1980) , argued forcefully in favor of acting as if trace fos-
sil names were covered by the Code while petitioning the International
Commission for Zoological Nomenclature to amend the Code to include
ichnotaxa. Most ichnologists followed this advice, and in its fourth edition
(1985 ), the Code was revised to include names for “the work of animals” again,
with the proviso that only fossil examples be included. Rindsberg (1990)
reported on this progress and pointed out some remaining problems, which were
discussed by the taxonomic community and largely resolved in the fifth edition
of the Code (1999).