The order Basslerocerida was established (erected in the odd parlance) by Rousseau Flower (1950) for nautiloides intermediate between straight shelled Ellesmerocerida and coiled Tarphycerida. Species included are in general, exgastrically cyrotoconic, curved like an old rocking chair rocker. Through the powers of evolution the upwardly curved shells became wound back on them selves, first as open, gyroconic spirals, then serpenticones with whorls in contact, true tarphycerids So what happened to them other than that.
Well first of all they did not disappear from the fossil record or vanish from time. The order simply stopped being used, except in historical reference. Flower (1976) simply abandoned the order and included the Bassleroceratidae in the Tarphycerida as the ancestral family, whereas William Furnish and Brian Glennister previously (1964) had included them in the Ellesmerocerida. Take your pick. Either works. As for me, I go along this time with Furnish and Glennister, for what ever it's worth which probably isn't all that much, leaving Tarphycerida for truly coiled forms.
Rousseau Flower and Bernhard Kummel, 1950. A Classification of the Nautiloidea - Journal of Paleontology
Rousseau Flower, 1976, Ordovician Cephalopod Faunas and Their Role in Correlation -Palaeontological Assoc.
William Furnish and Brian Glennister, 1964. Nautiloidea - Ellesmerocerida. --Treatise on Invertebrate Paleontology
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