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Posted: Aug 30 2007

 Trachycardium egmontianum (Linnaeus, 1758), and comparison to Dallocardia muricatum (previously Trachycardium muricatum)

Note:  This same presentation is used for both species, so be careful not to confuse the comments applicable to one but not the other.

Comment added May, 2013: Abbott (American Seashells 1974) included muricatum within the Genus Trachycardium Mörch, 1853 and the Subgenus Dallocardia Stewart, 1930. Since that time Dallocardia Stewart, 1930 has been more and more accepted at the full generic level and many of the most recent publications present the taxon as Dallocardia muricata (Linneaus, 1758).

I'd like to update the labels on these slides, but it's too big a job. So, read "Trachycardium muricatum ," but think "Dallocardia muricata."

Note regarding T. egmontianum: Harry Lee, frequent shell show judge and among the top experts on Florida mollusks, has pointed out that according to ICZN code T. egmontianum should be treated as a junior synonym to Trachycardium mindanaensis (Reeve, 1844). However, most collectors (including Harry) believe our western Atlantic shell should be formally identified as T. egmontianum, as it continues to be so identified most often. Harry's following post from Conch-L explains the issue:

Dear Listers,

In 2004 from 3/6 to 3/8 and 4/3 to 4/4 there were ten Conch-L postings on the nomenclatorial cloud surrounding Cardium mindanense Reeve, 1844 and C. egmontianum Shuttleworth, 1856.

The testy issue was which of two type designations published in the 1990's held sway in determining the identity of the former species, which was based on three syntypes, only one (the one Reeve illustrated!) of which was the Carolinian-Bahamian cockle we have correctly come to recognize as a Trachycardium under the latter name. The other two represent an Indo-Pacific species.

With considerable help from Dick Petit, I decided that this conundrum required the application of the plenary powers of ... you guessed it ... that august council discussed many times in this forum, the International Commission for Zoological Nomenclature (ICZN).

I'll try to remember to post a link to the ICZN Ruling on the petition, which can be expected within the next two years or so.


Date: Tue, 1 Jul 2008
Sender: Conchologists List <CONCH-L@LISTSERV.UGA.EDU>
From: "
Harry G. Lee" <shells@HGLEE.COM>
Subject: Prickly Cockle issues

Today, not much over a year since the petition was published, I received news that:

"The Commission has ruled that the current usage of the specific name egmontianum for a common and widespread western Atlantic bivalve Trachycardium egmontianum (Shuttleworth, 1856) of the family CARDIIDAE is conserved by setting aside all lectotype designations for Cardium mindanense Reeve, 1844 prior to that by Vidal (1998)."

The ruling of the Commission is as follows:

Bulletin of Zoological Nomenclature 65(2) June 2008

OPINION 2197 (Case 3341)
Cardium egmontianum Shuttleworth, 1856 (currently Trachycardium egmontianum; Mollusca, Bivalvia, CARDIIDAE): current usage conserved Abstract. The Commission has ruled that the current usage of the specific name egmontianum for a common and widespread western Atlantic bivalve Trachycardium egmontianum (Shuttleworth, 1856) of the family CARDIIDAE is conserved by setting aside all lectotype designations for Cardium mindanense Reeve, 1844 prior to that by Vidal (1998).

Keywords. Nomenclature; taxonomy; Mollusca; Bivalvia; CARDIIDAE; Trachycardium; Cardium mindanense; Cardium egmontianum.

(1) Under the plenary power it is hereby ruled that all lectotype designations for
Cardium mindanense Reeve, 1844 prior to that by Vidal (1998) are set aside.
(2) The following names are hereby placed on the Official List of Specific Names
in Zoology:
      (a) mindanense Reeve, 1844, as published in the binomen Cardium mindanense and as defined by the lectotype designated by Vidal (1998);
      (b) egmontianum Shuttleworth, 1856, as published in the binomen Cardium egmontianum.

History of Case 3341
An application to conserve the usage of the specific name of Cardium egmontianum Shuttleworth, 1856 was received from Harry G. Lee (Jacksonville, FL, U.S.A.) and Richard E. Petit (North Myrtle Beach, SC, U.S.A.) on 2 March 2005. This requested setting aside a lectotype designation by Voskuil & Onverwagt (1992) that made Cardium mindanense a senior synonym of C. egmontianum and removing the name C. mindanense from usage for an Indo-Pacific species. After correspondence the case was published in BZN 64: 12–14 (March 2007). The title, abstract and keywords of the case were published on the Commission’s website. One supportive comment on this case was published in BZN 64(3): 185.

Decision of the Commission
On 1 December 2007 the members of the Commission were invited to vote on the proposals published in BZN 64: 14. At the close of the voting period on 1March 2008 the votes were as follows:

Affirmative votes – 16: Alonso-Zarazaga, Bogutskaya, Bouchet, Brothers, Fautin, Halliday, Krell, Kullander, Lamas, Mawatari, Pape, Papp, Patterson, Rosenberg, van Tol and Zhang.
Negative votes – 4: Grygier, Kottelat, Ng and Štys.
No vote was received from Lim. Kerzhner, Minelli and Pyle were on leave of absence.

Voting against, Grygier commented that if the ‘type designation’ of Voskuil & Onverwagt was not valid (as certainly appears to be the case), then there was no reason to invoke the plenary power, which pertains to suspension of the application of some provision of the Code (Article 78.1). He says that in this application the applicant simply wants the Commission to declare the type designation in question not valid ‘to remove any question’. This should be done under the specific power to ‘interpret or apply the provisions of the Code to any question of zoological nomenclature’ granted to the Commission by Article 78.2.3, not under the plenary power. He suggested that following the vote, an Opinion of the sort described in Article 80.2.1 should be issued. Kottelat concurs, saying that although he has not been able to examine the original description and the ‘lectotype’ designation, the way the application describes the ‘lectotype’ designation by Voskuil & Onverwagt makes it clear that it is not a lectotype designation and that the lectotype designation by Vidal is valid. Therefore no decision by the Commission is needed and the use of plenary powers is not justified. Ng had similar sentiments, saying that while it may be argued that this case pertains to interpretation of what Voskuil & Onverwagt actually did, the arguments suggest that the supposed lectotype designation was invalid and was made as a passing comment. As the Code stands, this lectotype designation has no validity and as such, this case is unnecessary. Štys brings a similar set of observations, saying that Lee & Petit’s solution to the situation is of course correct. However, he does not see any reason to invoke plenary power for cases in which normal application of the Code is sufficient. Voskuil & Onverwagt’s (1992) designation of holotype for Cardium mindanense was invalid (Article 73.1.3) and was insufficient for fixation of a lectotype by inference of a ‘holotype’ (Article 74.6).

Original references
The following are the original references to the names placed on an Official List by the ruling given in the present Opinion:

mindanense, Cardium, Reeve, 1844, Conchologia Iconica, vol. 2. Pl. 4, fig. 19. egmontianum, Cardium, Shuttleworth, 1856, Journal de Conchyliologie, 5: 172–173.

The following is the reference for the designation of the lectotype for Cardium mindanense Reeve, 1844:

Vidal, J. 1998. Apex, 13: 115.

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