@article {3169,
	title = {A new genus of mellitid sand dollar (Echinoidea: Mellitidae) from the      eastern Pacific coast of the Americas
},
	journal = {Zootaxa},
	volume = {4111},
	year = {2016},
	month = {2016/5/13},
	pages = {158-166},
	address = {New Zealand},
	abstract = {Lanthonia gen. nov. Coppard 2016 is a genus of clypeasteroid sand dollar      whose members inhabit shallow, sandy waters from Mexico (including the
      Gulf of California) to Colombia in the tropical and subtropical eastern
      Pacific. Lanthonia includes Lanthonia longifissa (Michelin, 1858) and
      Lanthonia grantii (Mortensen, 1948), with L. longifissa hereby designated
      as the type species. Both L. longifissa and L. grantii were previously
      placed in the genus Mellita (L. Agassiz, 1841). However, levels of genetic
      divergence between a lineage containing L. longifissa and L. grantii and a
      lineage containing all other species of Mellita, including the type
      species M. quinquiesperforata (Leske, 1778), indicate genus level
      differentiation. The systematic interpretation of this group also supports
      the designation of this new genus as it allows the tree topology to be
      recovered from the nomenclature and clarifies the historical biogeography
      of these clades. This has resulted in members of both lineages today being
      sympatric in the eastern Pacific. Members of Lanthonia are morphologically
      differentiated from the type species of Mellita and all Pacific Mellita in
      having very narrow ambulacral regions between the food grooves and the
      ambulacral lunules on the oral surface, these being very broad in both M.
      quinquiesperforata and M. notabilis. The dentation of the bidentate
      pedicellariae also differentiate these genera, with small peripheral teeth
      present along the edge of the blade in species of Lanthonia and one to
      three enlarged intersecting teeth present distally in all species of
      Mellita.
},
	isbn = {1175-5334},
	url = {http://dx.doi.org/10.11646/zootaxa.4111.2.4https://www.ncbi.nlm.nih.gov/pubmed/27394905},
	author = {Coppard, Simon E}
}
