...Fig. 2 Stratigraphy and graptolite biozones of the early Silurian levels referred to in the text, showing the ranges of Huttagraptus acinaces (the senior synonym of M. rheidolensis ), Neolagarograptus rickardsi and N. tenuis ; after Zalasiewicz et al . 2007 , 2009 . ...

..., it possesses more complex, geniculate, thecae, with well-developed thecal hoods, and probably represents one of the earliest Huttagraptus species. Huttagraptus ? praematurus has a range restricted to the lower atavus Biozone and may be a subzonal marker for that interval. The roots of Coronograptus are obscure...

... are Coronograptus gregarius gregarius (although this species possibly originates in the upper acinaces Biozone), Pribylograptus argutus argutus and Metaclimacograptus undulatus ( Fig. 12 ). Some taxa continue from the previous biozone, notably Atavograptus atavus , Huttagraptus acinaces , Normalograptus...

.... 3 ), may be referred to the higher part of the atavus Biozone of Hutt (1974a) , whereas Toghill (1968b) found these two species in the suprajacent acinaces Biozone. The biozonal index Huttagraptus acinaces (Törnquist) itself is missing in our section and elsewhere in peri-Gondwanan Europe...

... Koren’ & Rickards; 341-4; 977.94 m. (e) Paraclimacograptus innotatus (Nicholson); 341-5; 977.94 m. (f ) ‘ Monograptus’ difformis Törnquist; 341-6; 975.45 m. (g) ‘ Monograptus’ vulgaris Hutt; 341-7; 976.40 m. (h, n) Huttagraptus ? sp.; 975.45 m; (h) 341-8; (n) 341-14. (i) Huttagraptus acinaces...

... acinaces Biozone in Asker ( Fig. 2 ). The base of the succeeding Leangen Member is dated to the base of Aeronian, according to the Stricklandia lens (Sowerby, 1839 )/ Stricklandia laevis (Sowerby, 1839 ) lineage and the base of the overlying Rytteråker Formation is from the S . sedgwickii Biozone...