The fossil genus Heterocladus LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003 was established based on specimens from the Silurian (Llandovery) of southeastern Wisconsin, USA (LoDuca et al., Reference LoDuca, Kluessendorf and Mikulic2003). This genus is monotypic and contains only the type species Heterocladus waukeshaensis LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003, regarded as a noncalcified dasycladalean alga (LoDuca et al., Reference LoDuca, Kluessendorf and Mikulic2003). Heterocladus waukeshaensis shows a narrow, undivided main axis and two types of laterals. Hair-like, branched laterals are arranged in whorls at lower part of the main axis, whereas clavate, undivided laterals appear at the upper part (LoDuca et al., Reference LoDuca, Kluessendorf and Mikulic2003). The generic name is derived from the Greek hetero and klados, meaning ‘different’ and ‘branches,’ respectively (LoDuca et al., Reference LoDuca, Kluessendorf and Mikulic2003).
However, Heterocladus LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003 is a later homonym of Heterocladus Turczaninow, Reference Turczaninow1847, a name that was validly published based on an extant angiosperm (Turczaninow, Reference Turczaninow1847). Heterocladus Turczaninow, Reference Turczaninow1847 is currently regarded as a taxonomic synonym of Coriaria Linnaeus, Reference Linnaeus1753 (Good, Reference Good1930; Skog, Reference Skog1972).
According to Articles 11.3 and 53.1 of the International Code of Nomenclature for Algae, Fungi, and Plants (Shenzhen Code) (Turland et al., Reference Turland, Wiersema, Barrie, Greuter, Hawksworth, Herendeen, Knapp, Kusber, Li, Marhold, May, McNeill, Monro, Prado, Price and Smith2018), Heterocladus LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003 should not be used because this name is illegitimate. Hence, the replacement name Jimaodanus is proposed here to replace Heterocladus LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003. The replacement name is derived from jīmáodǎnzi, the Chinese name of a feather duster, referring to morphological characters of the laterals.
Systematic paleontology
Genus Jimaodanus nom. nov.
- Reference LoDuca, Kluessendorf and Mikulic2003
Heterocladus LoDuca, Kluessendorf, and Mikulic, p. 1152, fig. 1.
Type species
Jimaodanus waukeshaensis (LoDuca, Kluessendorf, and Mikulic) comb. nov., from Wisconsin of USA, monotypy; figured by LoDuca et al. (Reference LoDuca, Kluessendorf and Mikulic2003, fig. 1).
Diagnosis
See LoDuca et al. (Reference LoDuca, Kluessendorf and Mikulic2003, p. 1152).
Occurrence
Brandon Bridge Formation, Silurian (Llandovery); Waukesha Lime and Stone Company quarry, north of Waukesha, Wisconsin, USA.
Etymology
From jīmáodǎnzi, the Chinese name of feather duster, referring to morphological characters of the laterals.
Remarks
The genus Heterocladus LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003 is a later homonym of Heterocladus Turczaninow, 1847. Therefore, the replacement generic name Jimaodanus is proposed to replace Heterocladus LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003.
Jimaodanus waukeshaensis (LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003) comb. nov.
- Reference LoDuca, Kluessendorf and Mikulic2003
Basionym: Heterocladus waukeshaensis LoDuca, Kluessendorf, and Mikulic, p. 1155, fig. 1-1, 1-2.
Holotype
Field Museum of Natural History, FMNH PP 45959a, b, Wisconsin, USA.
Diagnosis
See LoDuca et al. (Reference LoDuca, Kluessendorf and Mikulic2003, p. 1155).
Occurrence
Brandon Bridge Formation, Silurian (lower Llandovery); Waukesha Lime and Stone Company quarry, north of Waukesha, Wisconsin, USA.
Description
See LoDuca et al. (Reference LoDuca, Kluessendorf and Mikulic2003, p. 1155).
Remarks
The species Heterocladus waukeshaensis LoDuca, Kluessendorf, and Mikulic, Reference LoDuca, Kluessendorf and Mikulic2003 was illegitimate due to the generic name used previously for the extant angiosperm. Hence, a new combination is here proposed.
Acknowledgments
I thank J. Xiu of Friedrich Schiller University Jena for providing important literature. The work was supported by the National Natural Science Foundation of China (grant no. 41802003).
Declaration of competing interests
The author declares none.