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Ghost shrimp Calliax de Saint Laurent, 1973 (Decapoda: Axiidea: Callianassidae) in the fossil record: systematics, palaeoecology and palaeobiogeography.

Hyžný M, Gašparič R - Zootaxa (2014)

Bottom Line: Thorough comparison of extant members of the genus resulted in evaluation of characters present on chelipeds being taxonomically important on the genus level, specifically: 1) rectangular major P1 propodus with two ridges on the base of the fixed finger extending onto manus; 2) major P1 fingers relatively short; and 3) minor P1 chela with dactylus longer than fixed finger and possessing a wide gap between fingers.The known geographic distribution of C. michelottii is expanded by the first confirmed occurrence of the species in Slovakia.Based on the scarce fossil record known to date, Calliax has a Tethyan origin; it supposedly migrated westward to establish present day communities in the Caribbean sometime before the Middle Miocene.

View Article: PubMed Central - PubMed

Affiliation: Geological-Paleontological Department, Natural History Museum, Vienna, Burgring 7, A-1010 Vienna, Austria.; Email: matus.hyzny@nhm-wien.ac.at.

ABSTRACT
Ghost shrimps of the family Callianassidae are very common in the fossil record, but mostly as isolated cheliped elements only. The assignment to biologically defined genera, diagnosed on the basis of soft part morphology, is thus rather difficult. In this respect, proxy characters present on chelipeds that are the most durable ghost shrimp remains are needed to ascribe fossil material to extant genera. The genus Calliax de Saint Laurent, 1973 has been particularly obscure in this respect. Thorough comparison of extant members of the genus resulted in evaluation of characters present on chelipeds being taxonomically important on the genus level, specifically: 1) rectangular major P1 propodus with two ridges on the base of the fixed finger extending onto manus; 2) major P1 fingers relatively short; and 3) minor P1 chela with dactylus longer than fixed finger and possessing a wide gap between fingers. On this basis, Callianassa michelottii A. Milne Edwards, 1860, from the Oligocene and Miocene of Europe is herein reassigned to Calliax. Further re-examination of the ghost shrimp fossil record revealed that C. szobensis Müller, 1984, from the Middle Miocene of Hungary represents the same animal as C. michelottii and they are synomymised herein. The known geographic distribution of C. michelottii is expanded by the first confirmed occurrence of the species in Slovakia. All occurrences of C. michelottii known to date are reviewed and documented. The presence of Calliax michelottii comb. nov. may be considered an indicator of deeper marine settings. Based on the scarce fossil record known to date, Calliax has a Tethyan origin; it supposedly migrated westward to establish present day communities in the Caribbean sometime before the Middle Miocene.

No MeSH data available.


Related in: MedlinePlus

Calliax michelottii (A. Milne Edwards, 1860) comb. nov. from the Middle Miocene of Kamnik, Slovenia. A, RGA/SMNH 0754, right propodus; B, RGA/SMNH 0779, left propodus; C, RGA/SMNH 0864, right propodus; D, RGA/SMNH 0773, left propodus; E, RGA/SMNH 1191, left major chela consisting of propodus, carpus and merus; F, RGA/SMNH 1075, left propodus articulated with dactylus; G, RGA/SMNH 1187, left propodus articulated with dactylus; H, RGA/SMNH 1069, left major chela consisting of dactylus, propodus and carpus; I , GBA 2009/014/0027, right propodus. All specimens are to scale and were covered with ammonium chloride prior to photography. Scale bar equals 5 mm.
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Figure 9: Calliax michelottii (A. Milne Edwards, 1860) comb. nov. from the Middle Miocene of Kamnik, Slovenia. A, RGA/SMNH 0754, right propodus; B, RGA/SMNH 0779, left propodus; C, RGA/SMNH 0864, right propodus; D, RGA/SMNH 0773, left propodus; E, RGA/SMNH 1191, left major chela consisting of propodus, carpus and merus; F, RGA/SMNH 1075, left propodus articulated with dactylus; G, RGA/SMNH 1187, left propodus articulated with dactylus; H, RGA/SMNH 1069, left major chela consisting of dactylus, propodus and carpus; I , GBA 2009/014/0027, right propodus. All specimens are to scale and were covered with ammonium chloride prior to photography. Scale bar equals 5 mm.

Mentions: The best preserved and most numerous remains of Calliax in the fossil record belong to species originally described as Callianassa michelottii (Figs 5–10). It is discussed in detail below.


Ghost shrimp Calliax de Saint Laurent, 1973 (Decapoda: Axiidea: Callianassidae) in the fossil record: systematics, palaeoecology and palaeobiogeography.

Hyžný M, Gašparič R - Zootaxa (2014)

Calliax michelottii (A. Milne Edwards, 1860) comb. nov. from the Middle Miocene of Kamnik, Slovenia. A, RGA/SMNH 0754, right propodus; B, RGA/SMNH 0779, left propodus; C, RGA/SMNH 0864, right propodus; D, RGA/SMNH 0773, left propodus; E, RGA/SMNH 1191, left major chela consisting of propodus, carpus and merus; F, RGA/SMNH 1075, left propodus articulated with dactylus; G, RGA/SMNH 1187, left propodus articulated with dactylus; H, RGA/SMNH 1069, left major chela consisting of dactylus, propodus and carpus; I , GBA 2009/014/0027, right propodus. All specimens are to scale and were covered with ammonium chloride prior to photography. Scale bar equals 5 mm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4402405&req=5

Figure 9: Calliax michelottii (A. Milne Edwards, 1860) comb. nov. from the Middle Miocene of Kamnik, Slovenia. A, RGA/SMNH 0754, right propodus; B, RGA/SMNH 0779, left propodus; C, RGA/SMNH 0864, right propodus; D, RGA/SMNH 0773, left propodus; E, RGA/SMNH 1191, left major chela consisting of propodus, carpus and merus; F, RGA/SMNH 1075, left propodus articulated with dactylus; G, RGA/SMNH 1187, left propodus articulated with dactylus; H, RGA/SMNH 1069, left major chela consisting of dactylus, propodus and carpus; I , GBA 2009/014/0027, right propodus. All specimens are to scale and were covered with ammonium chloride prior to photography. Scale bar equals 5 mm.
Mentions: The best preserved and most numerous remains of Calliax in the fossil record belong to species originally described as Callianassa michelottii (Figs 5–10). It is discussed in detail below.

Bottom Line: Thorough comparison of extant members of the genus resulted in evaluation of characters present on chelipeds being taxonomically important on the genus level, specifically: 1) rectangular major P1 propodus with two ridges on the base of the fixed finger extending onto manus; 2) major P1 fingers relatively short; and 3) minor P1 chela with dactylus longer than fixed finger and possessing a wide gap between fingers.The known geographic distribution of C. michelottii is expanded by the first confirmed occurrence of the species in Slovakia.Based on the scarce fossil record known to date, Calliax has a Tethyan origin; it supposedly migrated westward to establish present day communities in the Caribbean sometime before the Middle Miocene.

View Article: PubMed Central - PubMed

Affiliation: Geological-Paleontological Department, Natural History Museum, Vienna, Burgring 7, A-1010 Vienna, Austria.; Email: matus.hyzny@nhm-wien.ac.at.

ABSTRACT
Ghost shrimps of the family Callianassidae are very common in the fossil record, but mostly as isolated cheliped elements only. The assignment to biologically defined genera, diagnosed on the basis of soft part morphology, is thus rather difficult. In this respect, proxy characters present on chelipeds that are the most durable ghost shrimp remains are needed to ascribe fossil material to extant genera. The genus Calliax de Saint Laurent, 1973 has been particularly obscure in this respect. Thorough comparison of extant members of the genus resulted in evaluation of characters present on chelipeds being taxonomically important on the genus level, specifically: 1) rectangular major P1 propodus with two ridges on the base of the fixed finger extending onto manus; 2) major P1 fingers relatively short; and 3) minor P1 chela with dactylus longer than fixed finger and possessing a wide gap between fingers. On this basis, Callianassa michelottii A. Milne Edwards, 1860, from the Oligocene and Miocene of Europe is herein reassigned to Calliax. Further re-examination of the ghost shrimp fossil record revealed that C. szobensis Müller, 1984, from the Middle Miocene of Hungary represents the same animal as C. michelottii and they are synomymised herein. The known geographic distribution of C. michelottii is expanded by the first confirmed occurrence of the species in Slovakia. All occurrences of C. michelottii known to date are reviewed and documented. The presence of Calliax michelottii comb. nov. may be considered an indicator of deeper marine settings. Based on the scarce fossil record known to date, Calliax has a Tethyan origin; it supposedly migrated westward to establish present day communities in the Caribbean sometime before the Middle Miocene.

No MeSH data available.


Related in: MedlinePlus