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The BRISTOLIA family trilobite collection


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Since last year, I was starting hunting down all types of Bristolia genus. I am so fascinating about its shape. Here represents all the species I have acquired: 

 

Bristolia bristolensis (Resser 1928)

 

Types: USNM 78390, the lectotype (defined in Palmer and Repina 1993); paralectotypes USNM 78391 and 78392.

 

Bristolia bristolensis had originally been recognized (e.g., Riccio 1952; Palmer and Halley 1979; Palmer and Repina 1993) as a highly variable species, particularly in the condition of the intergenal and genal spine angles. However, Lieberman (1998) used univariate measurements and statistical analyses to define a well-constrained B. bristolensis based on Resser’s (1928) lectotype, and demonstrated that what had traditionally been treated as a broadly variable B. bristolensis was actually two different species. The species referred to as Bristolia n. sp. in Lieberman (1998) is described here as B. harringtoni n. sp. Bristolia bristolensis has the intergenal angle deflected at an 80 to 95 degree angle relative to a transverse line and the genal spine angle is variably developed opposite and/or between the distal tips of S2 and S3. In B. harringtoni the intergenal angle is deflected at a 50 to 65 degree angle relative to a transverse line and the genal spine angle is developed variably opposite the distal tip of S2 or the medial part of L1.

 

Occurrence: California: the Carrara Formation, in the lower Bristolia zonule, upper part of the Olenellus zone, Early Cambrian, following Nelson (1976) and Palmer and Halley (1979), in the Grapevine, Funeral and Resting Spring ranges, the White-Inyo/Death Valley region, and in the Latham Shale, Marble Mountains, 190 m W of the limestone quarry, 0.5 mi E of Cadiz, in the Mojave Desert portion of San Bernardino County, possibly equivalent to Hazzard’s (1933) locality M-5, treated as in the Bristolia zonule. 

 

The above content comes from paper: Systematic Revision of the Olenelloidea (Trilobita, Cambrian) Bulletin 5 of the Peabody Museum of Natural History Yale University 18 October 1999 New Haven, Connecticut

 

5e4d22b869225_Bristoliabritolensis.thumb.jpg.b3f88d34daec93dc4e0d70e2d7932153.jpg

 

Bristolia Insolens (Resser, 1928)

5e4d23085bd09_BristoliainsolensResser1928.jpg.d28cd8fb0f923398961ceaa191f4d628.jpg

 

Bristolia cf. parryi 

5e4d231059096_Bristoliaparryi.thumb.jpg.5a8971d6d6151573cc6f38cec3f05b78.jpg

 

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