Here is a rare trilobite specimen of the species Burlingia halgedahlae from the Marjum Formation in Utah.
This specimen impresses with its contrast-rich and detailed preservation.
The Burlingia itself measures about 5 mm in length. Burlingia is rarly larger than 10 mm.
Additionally, the genus is very thin-shelled, which makes well-preserved specimens like this one with complete shell preservation rare.
The genus Burlingia has been known to fossil collectors from the Marjum Formation in Utah for some time and was mostly described as Burlingia sp. or Burlingia cf. hectori (Walcott, 1908).
However, the species Burlingia halgedahlae was recently been described by Robison & Babcock in 2011. And indeed, Robison & Babcock also point out the similarity to Burlingia hectori, which is known from the Stephen Formation of the Burgess Shale.
The family Burlingiidae is systematically very interesting. Although it is placed in the class Trilobita, it is not assigned to any specific order, making its position problematic (incertae sedis).
A possible association with the order Nektaspida has been discussed. Fortey in Kaesler (1997) describes the family Naraoiidae as follow : "Naraoiidae is regarded as the sister group of the calcified Trilobita".
However, the family Burlingiidae is undoubtedly placed in the order of trilobites due to its calcified shell.
A relationship with the Eodiscina or the Ptychopariida is considered largely outdated.
The Burlingiidae share some features with exotic representatives of the order Redlichiida.
Ebbestad & Budd (2003) draw comparisons with the Lower Cambrian trilobite species Kleptothule from the Sirius Passet Lagerstätte in the lower Cambrian of Greenland.
A relationship with the family Oryctocephalidae (order Corynexochida) has also been discussed due to the similar lateral expression of the glabellar furrows. However, in the Burlingiidae, the glabellar furrows are invisible in younger specimens and appear only in more mature specimens.
The similarities in the pygidia of Burlingia could be a primitive feature shared with both Oryctocephalidae and Redlichiidae.
The genus Burlingia is almost globally distributed, but rather known through isolated finds.
Ebbestad, J.O.; Budd, G.D. (2003). "Burlingiid trilobites from Norway, with a discussion of their affinities and relationships". Palaeontology. 45 (6): 1171–1195. doi:10.1111/1475-4983.00281.
Fortey, R. A. (1997), "Classification", in Kaesler, R. L. (ed.), Treatise on Invertebrate Paleontology, Part O, Arthropoda 1, Trilobita, revised. Volume 1: Introduction, Order Agnostida, Order Redlichiida, Boulder, CO & Lawrence, KS: The Geological Society of America, Inc. & The University of Kansas, pp. 289–302, ISBN 978-0-8137-3115-5
Robison, Richard A.; Babcock, Loren E. (2011-11-30). "Systematics, paleobiology, and taphonomy of some exceptionally preserved trilobites from Cambrian Lagerstätten of Utah". Paleontological Contributions (5): 1–47. doi:10.17161/PC.1808.8543. ISSN 1946-0279 |
