TANGLEFOOT MOUNTAIN TRILOBITES

After a phenomenal collecting trip to the Goat Haven Mountain of the East Kootenay region near Cranbrook, we headed out to the classic Tanglefoot site following in the footsteps of Brian Chatterton. 

Brian Chatterton has been visiting the East Kootenay region for many years. In 1998, he and Rolf Ludvigsen published the pivotal work on the "calcified trilobites" we had begun hearing about in the late 1990s. 

There were tales of blue trilobites in calcified layers guarded by a resident Grizzly. This was years before logging roads had reached this pocket of paleontological goodness and hiking in — bear or no bear — was a daunting task. 

In his Cambridge University Press paper, Chatterton describes the well-preserved fauna of largely articulated trilobites from three new localities in the Bull River Valley. 

All the trilobites from these localities are from the lower or middle part of the Wujiajiania lyndasmithae Subzone of the Elvinia Zone, lower Jiangshanian, in the McKay Group. 

Access is via a bumpy ride on logging roads 20 km northeast of Fort Steele that includes fording a river (for those blessed with large tires and a high wheelbase) and culminating in a hot, dusty hike and death-defying 5-story traipse down a 35-degree slope to the localities.

Two new species were proposed with types from these localities: Aciculolenus askewi and Cliffia nicoleae. 

The trilobite (and agnostid) fauna from these localities includes at least 20 species that read like a who's who of East Kootenay palaeontology: 

Aciculolenus askewi n. sp., Agnostotes orientalis (Kobayashi, 1935), Cernuolimbus ludvigseni Chatterton and Gibb, 2016, Cliffia nicoleae n. sp., Elvinia roemeri (Shumard, 1861), Grandagnostus? species 1 of Chatterton and Gibb, 2016, Eugonocare? phillipi Chatterton and Gibb, 2016, Eugonocare? sp. A, Housia vacuna (Walcott, 1912), Irvingella convexa (Kobayashi, 1935), Irvingella flohri Resser, 1942, Irvingella species B Chatterton and Gibb, 2016, Olenaspella chrisnewi Chatterton and Gibb, 2016, Proceratopyge canadensis (Chatterton and Ludvigsen, 1998), Proceratopyge rectispinata (Troedsson, 1937), Pseudagnostus cf. P. josepha (Hall, 1863), Pseudagnostus securiger (Lake, 1906), Pseudeugonocare bispinatum (Kobayashi, 1962), Pterocephalia sp., and Wujiajiania lyndasmithae Chatterton and Gibb, 2016.

It has been the collaborative efforts of Guy Santucci, Chris New, Chris Jenkins, Don Askew and Stacey Gibb that has helped open up the region — including finding and identifying many new species or firsts including Pseudagnostus securiger, a widespread early Jiangshanian species not been previously recorded from southeastern British Columbia. 

Other interesting invertebrate fossils from these localities include brachiopods, rare trace fossils, a complete silica sponge (Hyalospongea), and a dendroid graptolite. 

The species we find here are more diverse than those from other localities of the same age in the region — and enjoy much better preservation. 

The birth of new species into our scientific nomenclature takes time and the gathering of enough material to justify a new species name. Fortunately for Labiostria gibbae, specimens had been found of this rare species had been documented from the upper part of Wujiajiania lyndasmithae Subzone — slightly younger in age. 

Combined with an earlier discovery, they provided adequate type material to propose the new species — Labiostria gibbae — a species that honours Stacey Gibb and which will likely prove useful for biostratigraphy.

Reference: https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/midfurongian-trilobites-and-agnostids-from-the-wujiajiania-lyndasmithae-subzone-of-the-elvinia-zone-mckay-group-southeastern-british-columbia-canada/E8DBC8BD635863E840715122C05BB14A#