. Breviora. BREVIORA No. 486. Figure 3. Scales on paratype of T. macintoshi, MCZ 2036. A) Loganella sp., two scales seen in cross section; B) Loganella sp., body scale in crown view showing unbroken posterolateral spinelets; CD) Loganella sp., body scales in crown view with small anterior basal process and posterolateral neck spinelets. The scales of the T. macintoshi specimens are large, up to mm long, and in an advanced stage of growth with well-developed bases (see Fig. 2A, PI. 1A-C); they are undoubtedly scales of a mature animal. They differ from European examples of T. parvidens (inc
. Breviora. BREVIORA No. 486. Figure 3. Scales on paratype of T. macintoshi, MCZ 2036. A) Loganella sp., two scales seen in cross section; B) Loganella sp., body scale in crown view showing unbroken posterolateral spinelets; CD) Loganella sp., body scales in crown view with small anterior basal process and posterolateral neck spinelets. The scales of the T. macintoshi specimens are large, up to mm long, and in an advanced stage of growth with well-developed bases (see Fig. 2A, PI. 1A-C); they are undoubtedly scales of a mature animal. They differ from European examples of T. parvidens (including the type specimen) in the clear expression of the numer- ous riblets on the neck region (PI. 2). However, as most European scales are waterworn to some degree it seems possible that the full extent of neck ribbing in the type species has never been clearly seen in the isolated scales. Gross did show one scale with 12 riblets on one side of the neck (1967, PI. 1, Fig. 3 A) but their number is usually much smaller. The slight differences in rib ornament on the neck of scales may reflect local variation within a single population of The- lodus parvidens. Furthermore, some of the specimens, including coprolitic masses and thin sections, show that scales of T. bicostatus type are part of the T. parvidens squamation (see Fig. 2). Despite the fact that the scales of T. bicostatus are very distinctive, both Gross (1967) and Turner (1973, 1976) thought they might be special scales of T. par- videns, while retaining the specific name bicostatus. One scale on the type specimen (MCZ 2035) appears to belong to T. trilobatus (see Fig. 1). A patch of small striated scales among the larger rhom- boid T. parvidens scales on specimen BMNH P52444 could also belong to T. trilobatus. Scales of this species are also seen in copro- litic masses (Fig. 2D-G). Thin sections of scales from the nodules. Please note that these images are extracted from scanned page images that may have been digitall
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