Dinehichnus, Lockley, dos Santos, Meyer, and Hunt, 1998
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publication ID |
https://doi.org/ 10.4202/app.00707.2019 |
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persistent identifier |
https://treatment.plazi.org/id/03DF87EE-FFC5-FFEC-FCB9-FBF142C9FEDD |
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treatment provided by |
Felipe |
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scientific name |
Dinehichnus |
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Dinehichnus isp.
Fig. 3 View Fig .
Material. —SHN.(JJS).ICNO.58, 60, 68, 109, 113; from Serra do Bouro, Boavista do Bouro, Pedra da Ulsa, Salir do Porto; Alcobaça (Kimmeridgian–lower Tithonian) and Freixial (middle–upper Tithonian) formations (for details see SOM: table S1).
Description. —Small to medium-sized (pes length 16.2– 24 cm) tridactyl tracks ( Fig. 3 View Fig and SOM: table S2), almost as wide as long (pes length/width ratio 0.89–1.08) with medium mesaxony (AT ratio 0.41–0.52). The tracks are robust and almost symmetrical, with a well-developed circular (to subquadrangular) metatarsophalangeal pad impression. One specimen (SHN.(JJS).ICNO.60) shows a quadripartite morphology, and no discrete phalangeal pad impressions have been recognized. A medial notch is slightly more developed in some specimens, so these tracks are slightly asymmetric. The digits are relatively robust; digit III is the longest, and digits II and IV are subequal in length, with variation in some specimens where digit IV is slightly longer than digit II. The hypices are quite symmetrical, with that of digit II located more proximally in some specimens. The distal end of the digit impressions is acuminated, showing slender and pointed claw marks in some specimens. The interdigital angle II–IV is medium (66–78°), interdigital angle II–III being generally greater than interdigital angle III–IV in the majority of the specimens.
Remarks.— Dinehichnus is the main formally named Late Jurassic ichnogenus assigned to medium-sized ornithopods. It has been described in several places in Europe (including the Lusitanian Basin), the USA, Africa and possibly Asia Lockley et al. 1998, 2008; Lockley 2009; Gierliński et al. 2009; Belvedere et al. 2010; Xing et al. 2014). Dinehichnus has also been identified in Early Cretaceous deposits in Europe (e.g., Lockley et al. 1998; Hornung and Reich 2012). The assignment of the studied tracks to this ichnotaxon is justified by the fact that the tracks have many of the features described in the diagnosis such as digit divarication, symmetry and especially the distinctive circular pad impression. The reason for not including the tracks in the type ichnospecies D. socialis is the fact that in our sample the quadripartite morphology described in the diagnosis of the ichnospecies is not clearly recognized.
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