Koremagraptus elegantulus, Rickards, R. B., Chapman, A. J., Wright, A. J. & Packham, G. H, 2003

Rickards, R. B., Chapman, A. J., Wright, A. J. & Packham, G. H, 2003, Dendroid and Tuboid Graptolites from the Llandovery (Silurian) of the Four Mile Creek Area, New South Wales, Records of the Australian Museum 55 (3), pp. 305-330 : 327-328

Koremagraptus elegantulus n.sp.

Fig. 22D

Material. HOLOTYPE AM F114752 from F14, Bridge Creek and PARATYPE AM F114717 a-b from W885, Bridge Creek .

Derivation of name. Reflecting the nature of the stipe pattern.

Diagnosis. Koremagraptus with gently diverging and anastomosing robust compound stipes 0.50–0.70 mm across; lacks recognizable autothecae.

Description. The large portion of rhabdosome measures 35 mm by 25 mm, and is typified by gently diverging and anastomosing robust stipes, each about 0.50–0.70 mm across except at points of anastomosis where they are wider. A number of twig-like terminations occur, often extending into the spaces formed by the anastomosing main stipes. Some of the “twigs” may terminate as single autothecal tubes. Autothecae have not been readily identified, however, and no thecal spacing figure is possible. All stipes are clearly compound with bundles of elongate thecae.

Remarks. Koremagraptus pseudoplexus Bouěek, 1957 from the Wenlock of Bohemia is one of the closest forms, having a similar pattern of stipes, but it is less robust than K. elegantulus and has frequent dissepiment-like branch connections which K. elegantulus lacks.

Figures

Fig.22.A,B. Thallograptus christoffersonae n.sp.: A,AM F114765, stipe development from basal holdfast, BF14 and B,AM F114746, holotype, F14; C, Koremagraptus obscurus n.sp. AM F114745,