Scyramathia A. Milne-Edwards, 1880

Tavares, Marcos & Santana, William, 2018, Refining the genus Rochinia A. Milne-Edwards, 1875: reinstatement of Scyramathia A. Milne-Edwards, 1880 and Anamathia Smith, 1885, and a new genus for Amathia crassa A. Milne-Edwards, 1879, with notes on its ontogeny (Crustacea: Brachyura: Epialtidae), Zootaxa 4418 (3), pp. 201-227 : 204-208

Scyramathia A. Milne-Edwards, 1880

Scyramathia A. MILNE-EDWARDS, 1880 : 356.

Type species. Amathia carpenteri NORMAN IN WyVILLE THOMSON, 1873 [SUBSEQUENT DESIGNATION By RATHBUN 1925, GENDER FEMININE].

Included species. Scyramathia carpenteri (NORMAN IN WyVILLE THOMSON, 1873) [ Amathia ] (EA, MD), Scyramathia umbonata (STIMPSON, 1871) [ Scyra ] (WA); AND Scyramathia boschii (CASADíO, FELDMANN, PARRAS & SCHWEITZER, 2005) n. comb. [ Rochinia ] [ MIOCENE OF PUERTO MADRyN, ARGENTINA, WA].

Material examined. Scyramathia carpenteri (NORMAN IN WyVILLE THOMSON, 1873): 1 FEMALE, 1 JUVENILE ( MCZ 6543), WEST AFRICA, OFF CAPE BAJADOR, TALISMAN EXPEDITION, 9.VII.1883, 882M.

Scyramathia umbonata (STIMPSON, 1871): FEMALE, CL 32 MM, CW 23 MM (MNRJ 1581), HOLOTyPE OF Rochinia confusa TAVARES, 1991, BRAZIL, RIO DE JANEIRO, R/V “MARION DUFRESNE”, TAAF MD/ BRAZIL 1987 , STN 64 CB 105, 23°46’S, 42°09’W, 02.VI.1987, 592–610M; 3 MALES, 1 OVIGEROUS FEMALE, 1 JUVENILE FEMALE (USNM 1000819), GULF OF MEXICO , LOUISIANA , SOUTHWEST OF GRAND ISLAND , NGOMCS EXPEDITION, R/V “CITATION”, 27°42’44”N, 91°32’55”W, 543–783M; 1 OVIGEROUS FEMALE (USNM 1191773), UNITED STATES, R/V “ OREGON II ” , STN 11580, 29°11’N, 87°55’W, 10.III.1971, 640M, W. SANTANA DET.; 1 MALE (MOUFPE 15448), BRAZIL, REVIZEE NORTE, PROSPECçÃO III, LANCE 2, 03°43’N, 48°53’W, 15.XI.1996, 186M; 1 OVIGEROUS FEMALE (MOUFPE 15449), PERNAMBUCO , REVIZEE NORDESTE, CRUZEIRO V, STN. 117, 08°13,2’N, 34°33.3’W, 19.XI.1999, 575M; 1 MALE, 6 FEMALES (MNRJ 13694), ESPíRITO SANTO , REVIZEE PESCA, STN D–0503, 19°39.943’S, 38°30.435’W, 29.VI.1999, 808M; 1 MALE CL 32MM, CW 23 MM (MZUSP 17424), 24°13.300’S, 43°10.600’W, XI–XII.1997, 690M; 1 MALE CL 57 MM, CW 43 MM (MZUSP 16228), F/V "KINPO MARU", LANCE 123, NO EXACT LOCALITy OR DEPTH; 1 MALE (MOUFPE 15469), REVIZEE, CRUISE 5/00, STN. 14, NO EXACT LOCALITy OR DEPTH.

Diagnosis. (BASED ON FULLy DEVELOPED SPECIMENS) CARAPACE SUPRAORBITAL, PREORBITAL, HEPATIC, MESOGASTRIC, PROTO-, MESO-, METABRANCHIAL, CARDIAC, INTESTINAL TUBERCLES LARGE, FLAT-TOPPED, SHOWING AS LEAF-LIKE PLATES . PREORBITAL SCUTELLATE PLATE AND HEPATIC BOLETATE ORNAMENTATION FUSED TOGETHER INTO LARGE, LEAF-LIKE PLATE. LATERAL AND MESIAL MARGINS OF ANTENNAL ARTICLES 2 + 3 DISTINCTLy EXPANDED INTO LOBES. PTERyGOSTOMIAL TEETH COALESCENT AT BASE, RATHER INDISTINCT DISTALLy FORMING PROMINENT PTERyGOSTOMIAL RIDGE. MALE CHELIPED SLENDER, MUCH LONGER THAN P2. CHELIPED PROPODUS STRONGLy COMPRESSED LATERALLy, FORMING DISTINCT EDGE ALONG ITS ENTIRE LENGTH. MALE THORACIC STERNITE 8 EXTENDING LATERALLy BEyOND STERNO-ABDOMINAL CAVITy, LEFT UNCOVERED LATERALLy By ABDOMEN, VISIBLE IN VENTRAL VIEW. MALE THORACIC STERNITES 4–7 WITH ONE STRONG, TRANSVERSE RIDGE EACH. MALE FOURTH THORACIC STERNITE TRANSVERSE RIDGE UNINTERRUPTED MEDIALLy, COMPLETE, LOOPING AROUND FOLLOWING ANTERIOR MARGIN OF STERNO-ABDOMINAL CAVITy. G1 REACHING FAR BEyOND THORACIC STERNAL SUTURE 4/5, RATHER STRAIGHT PROXIMALLy AND MEDIALLy, DISTINCTLy CURVED INWARDS SUBDISTALLy, CONVERGENT ANTERIORLy, TAPERING TO BLUNT TIP, LATERAL MARGINS GENTLy CURVED INWARDS DISTALLy ( FIG. 13A, B ).

Remarks. AS PREVIOUSLy MENTIONED, Scyramathia WAS ORIGINALLy ESTABLISHED FOR Amathia carpenteri AND Scyra umbonata , AND Scyramathia HAS LONG BEEN REGARDED AS A SyNONyM OF Rochinia A. MILNE-EDWARDS, 1875 (RATHBUN 1925; GRIFFIN & TRANTER 1986, TAVARES 1991; NG et al. 2008; TAVARES et al. 2016; LEE et al. 2017). HOWEVER, A COMPARISON BETWEEN S. carpenteri , S. umbonata AND Rochinia (BASED ON ITS TyPE SPECIES, R. gracilipes A. MILNE- EDWARDS, 1875) REVEALED THAT S. carpenteri AND S. umbonata CAN NO LONGER BE ATTRIBUTED TO Rochinia S. STR. THEREFORE, Scyramathia IS HEREIN RESURRECTED AS DISTINCT FROM Rochinia A. MILNE-EDWARDS, 1875 S. STR. Scyramathia AND Rochinia S. STR. DIFFER MARKEDLy FROM EACH OTHER IN THE FOLLOWING EIGHT CHARACTERS: 1) VERy STRONG MODIFICATIONS IN MORPHOLOGy OVER ONTOGENy REGARDLESS OF SEX, DURING WHICH THE CARAPACE SUPRAORBITAL, PREORBITAL, HEPATIC, MESOGASTRIC, PROTO-, MESO- AND METABRANCHIAL, CARDIAC, AND INTESTINAL TUBERCLES BECOME VERy LARGE, FLAT-TOPPED, LEAF- LIKE PLATES WHOSE CIRCUMFERENCES ARE BROADER THAN THE STEM IN FULL DEVELOPED SPECIMENS ( FIGS. 1A–D , 12C ), VS. ONLy SLIGHT CHANGES IN MORPHOLOGy OVER ONTOGENy IN Rochinia , IN WHICH THE CARAPACE IS FURNISHED WITH SUPRAORBITAL, PREORBITAL, HEPATIC, MESOGASTRIC, PROTO-, MESO- AND METABRANCHIAL, CARDIAC, AND INTESTINAL SPINES OR NODOSITIES IN FULL DEVELOPED SPECIMENS ( FIGS. 2A, B, E, F , 9D , 12A ); 2) PREORBITAL SCUTELLATE PLATE AND HEPATIC BOLETATE ORNAMENTATION FUSED TOGETHER INTO A LARGE, LEAF-LIKE PLATE, WHOSE CIRCUMFERENCE IS MUCH BROADER THAN THE STEM ( FIG. 1B, C ), VS. PREORBITAL AND HEPATIC PROMINENCES NOT FUSED TOGETHER, SPINIFORM IN Rochinia ( FIGS. 2A, B , 9D , 11A ); 3) MALE THORACIC STERNITE 8 EXTENDING LATERALLy BEyOND THE STERNO-ABDOMINAL CAVITy, SO THAT IT IS LEFT UNCOVERED LATERALLy By THE ABDOMEN AND THUS VISIBLE IN VENTRAL VIEW ( FIG. 1D ), VS. STERNITE 8 RESTRICTED TO THE STERNO-ABDOMINAL CAVITy, SO THUS CONCEALED By THE ABDOMINAL SOMITES AND THEREFORE NOT EXPOSED VENTRALLy IN Rochinia ( FIGS. 2C , 10A, B ); 4) LATERAL AND MESIAL MARGINS OF THE ANTENNAL ARTICLES 2 + 3 DISTINCTLy EXPANDED INTO LOBES ( FIG. 1D ), VS. ANTENNAL ARTICLES NOT EXPANDED INTO LOBES IN Rochinia ( FIG. 2D ); 5) MALE THORACIC STERNITES 4–7 WITH ONE STRONG TRANSVERSE RIDGE EACH ( FIG. 1D ), VS. NO THORACIC STERNAL TRANSVERSE RIDGES IN Rochinia ( FIG. 2C ); 6) PTERyGOSTOMIAL TEETH COALESCENT AT THE BASE, RATHER INDISTINCT DISTALLy FORMING A PROMINENT PTERyGOSTOMIAL RIDGE ( FIG. 1B, D ), VS. PTERyGOSTOMIAL TEETH VERy LOW, NOT COALESCENT ( FIG. 2B ); 7) G1 REACHING FAR BEyOND THE THORACIC STERNAL SUTURE 4/5, VS. G1 REACHING AT MOST SLIGHTLy BEyOND THE SUTURE 4/5 IN Rochinia ; 8) MALE CHELIPEDS SLENDER, LONGER THAN P2, WITH THE PROPODUS STRONGLy LATERALLy COMPRESSED, FORMING A DISTINCT DORSAL EDGE ALONG ITS ENTIRE LENGTH IN FULL GROWN SPECIMENS (SEE TAVARES et al., 2016: FIG. 3H ), VS. CHELIPEDS DISTINCTLy MASSIVE, SHORT, MUCH SHORTER THAN P2 IN Rochinia ( FIGS. 2A, B ). TAVARES (1991) SHOWED THAT THE RELATIVE LENGTH BETWEEN P1 AND P2 WAS A VALUABLE CHARACTER TO HELP DISTINGUISH BETWEEN GENERA. THE P1/P2 LENGTH RELATIVE TO EACH OTHER IN COMBINATION WITH OTHER MORPHOLOGICAL CHARACTERS WAS LATER USED By RICHER DE FORGES & NG (2009A) IN THE DIAGNOSIS OF THE GENERA Garthinia , Guinotinia , AND Laubierinia .

Scyramathia AND Rochinia ALSO DIFFER IN THEIR LARVAL STAGES (SEE INGLE 1979; LUPI & SPIVAK 2016). IN THE ZOEAL STAGES I AND II OF S. carpenteri , THE CARAPACE IS FURNISHED WITH ONE LATERAL SPINE AT EACH SIDE, VS. LATERAL SPINES ABSENT IN R. gracilipes ; THE ROSTRUM IS DISTINCTLy LONG IN S. carpenteri —AS LONG AS THE DORSAL SPINE, VS. MINUTE ROSTRUM IN Rochinia . IN THE MEGALOPAL STAGE OF S. carpenteri , THE CARAPACE HAS ONE STRONG CARDIAC SPINE AS WELL AS ONE SHORT SPINE IN THE BRANCHIAL REGION, VS. CARDIAC AND BRANCHIAL SPINES ABSENT IN R. gracilipes ; THE ROSTRUM IS REMARKABLy LONG IN S. carpenteri , VS. ROSTRUM VERy SHORT IN R. gracilipes ; AND THE PEREOPODS 2–4 WITH A COXAL AND ISCHIAL SPINE, VS. COXAL AND ISCHIAL SPINES ABSENT IN R. gracilipes .

Rochinia boschii CASADíO, FELDMANN, PARRAS & SCHWEITZER, 2005, DESCRIBED FROM THE MIOCENE OF PUERTO MADRyN, ARGENTINA, BASED ON yOUNG SPECIMENS WITH MAXIMUM CARAPACE WIDTH RANGING BETWEEN 20.2 MM AND 15.6 MM (CASADíO et al. 2005), CLOSELy RESEMBLES DEVELOPING SPECIMENS OF Scyramathia umbonata AND, ACCORDINGLy, IS TRANSFERRED TO Scyramathia .

Figures

FIGURE 1. Scyramathia umbonata (STImpSON, 1871), CEpHALOTHORAx. (A) MALE, CL 32mm, CW 23 mm, DORSAL VIEW (MZUSP 17424); (B–D) MALE, CL 57 mm, CW 43 mm, LATERAL, DORSAL AND VENTRAL VIEWS, RESpECTIVELy (MZUSP 16228). BLACk ARROWS (B, C) INDICATE pREORbITAL SCuTELLATE pLATE AND HEpATIC bOLETATE ORNAmENTATION fuSED TOGETHER INTO LARGE,LEAf-LIkE pLATE IN LATERAL AND DORSAL VIEWS, RESpECTIVELy. SOLID WHITE ARROWS (B, D) INDICATE pTERyGOSTOmIAL TEETH COALESCENT AT bASE, fORmING A pROmINENT pTERyGOSTOmIAL RIDGE IN LATERAL AND VENTRAL VIEWS, RESpECTIVELy. OuTLINED ARROW (D) INDICATES ANTEROLATERAL CORNER Of buCCAL fRAmE pROTRuDED INTO ROuNDEDLObE.GREyARROWS (D)INDICATE STRONG,TRANSVERSE RIDGESIN THORACIC STERNITES 5–7.BLACk ARROW(D) INDICATES THORACIC STERNITE 8 ExTENDING LATERALLybEyONDSTERNO-AbDOmINAL CAVITy,AND LEfT uNCOVEREDLATERALLy byAbDOmEN.SCALE bARS:20 mm.

FIGURE 2. Rochinia gracilipes A. MILNE-EDWARDS, 1875, mALE, CL 13 mm, CW 10 mm (MZUSP 12335). (A) HAbITuS DORSAL VIEW.(B)HAbITuS VENTRAL VIEW.(C) THORACICSTERNum AND AbDOmEN,CHELIpED AND pEREOpODS ELECTRONICALLyREmOVED.(D) DETAIL Of CEpHALOTHORAx ANTERIOR REGION SHOWING ANTENNAL ARTICLES 2+3 WITHOuT SpINES.(E) POSTERIOR LATERAL VIEW Of CARApACE SHOWING THORACIC pLEuRITES V–VII. (F) POSTERIOR VIEW Of CHEpHALOTHORAx AND AbDOmEN. NOTE IN C, STERNITE 8 COmpLETELy CONCEALED by AbDOmINAL SOmITES AND THEREfORE NOT ExpOSED VENTRALLy. ST7, THORACIC STERNITE 7. Ep7, THORACIC EpISTERNITE 7. PL7–PL5, THORACIC pLEuRITES 7–5 ExpOSED.SCALE bARS:5 mm.

FIGURE 9. Amathia agassizii SmITH, 1882, mALE, LECTOTypE, CL 27.5 mm, CW 20.3 mm (MCZ 3174), A juNIOR SyNONym Of Minyorhyncha crassa (A. MILNE-EDWARDS, 1879) n. gen., n. comb. (A) DORSAL HAbITuS. (B) DETAIL Of CEpHALOTHORAx ANTERIOR REGION, VENTRAL VIEW SHOWING ANTENNAL ARTICLES 2+3 WITH TWO DISTINCT SpINES (WHITE ARROWS). (C) DORSAL HAbITuS Of HOLOTypE Of Minyorhyncha crassa (A. MILNE-EDWARDS, 1879) n. gen., n. comb., mALE, CL 15.2 mm, CW 11.5mm (MCZ 2862). D, DORSAL HAbITuS Of LECTOTypE Of Rochinia gracilipes A. MILNE-EDWARDS, 1875, mALE, CL 15.0 mm, CW 11.4 mm (MCZ 1950). SCALE bARS: A, C 10 mm; B, 5 mm; D, 12 mm.

FIGURE 11. (A) Rochinia gracilipes A. MILNE-EDWARDS, 1875, LATERAL VIEW Of CEpHALOTHORAx, mALE CL 13 mm, CW 11 mm (MZUSP 2815). (B) Minyorhyncha crassa (A. MILNE-EDWARDS,1879) n. gen., n. comb., LATERAL VIEW Of CEpHALOTHORAx,mALE CL 58 mm, CW 46 mm (MZUSP 12843).Ab1, AbDOmINAL SOmITE 1, PL 5–7, THORACIC pLEuRITES 5–7 VISIbLE LATERALLy.SCALE bARS:A, 5 mm; B, 10 mm.

FIGURE 12. DORSAL VIEW Of CEpHALOTHORAx. (A) Rochinia gracilipes A. MILNE-EDWARDS, 1875, mALE, CL 13 mm, CW 10 mm (MZUSP 12335). (B) Anamathia rissoana (ROux, 1828), fEmALE, CL 22 mm, CW 19 mm (USNM 243897). (C) Scyramathia umbonata (STImpSON, 1871), mALE, CL 57 mm, CW 43 mm (MZUSP 16228). (D) Minyorhyncha crassa (A. MILNE-EDWARDS, 1879) n. gen., n. comb., mALE, CL 86 mm, CW 72 mm (MZUSP 28397). POS, HES, pOSTORbITAL AND HEpATIC SpINES, RESpECTIVELy. SCALE bARS:A, 5 mm; B, 10 mm; C, D 20 mm.

FIGURE 13. RIGHT mALE fIRST GONOpOD, DISTAL END, STERNAL (AbOVE) AND AbDOmINAL (bELOW) VIEWS, RESpECTIVELy. (A, B) Scyramathia umbonata (STImpSON,1871), CL 57 mm, CW 43 mm (MZUSP 16228). (C, D) Anamathia rissoana (ROux, 1828), CL 23 mm, CW 20 mm (USNM 152273). (E, F) Anamathia hystrix (STImpSON, 1871), mALE CL 26mm, CW 20 mm (MZUSP 16953). NOTE IN C–F kEEL (k) WELL DEVELOpED.(G, H) Minyorhyncha crassa n. gen., n. comb., CL 100 mm, CW 86 mm (MZUSP 13816). (I, J) Rochinia gracilipes A. MILNE-EDWARDS,1875, CL 18 mm, CW 14 mm (MZUSP 10835).SCALE bARS:1 mm.

FIGURE10. MALE Of Rochiniagracilipes A. MILNE-EDWARDS,1875.A, THORACIC STERNum AND AbDOmEN,mALE CL 13 mm,CW 10 mm (MZUSP 12335).B, AbDOmENREmOVED,mALE CL 13 mm, CW 11 mm (MZUSP 2815).(C, D) MALE Of Minyorhyncha crassa (A. MILNE-EDWARDS,1879) n. gen., n. comb.. (C) THORACIC STERNum AND AbDOmEN,mALE CL 58 mm, CW 46 mm (MZUSP 12843). (D) AbDOmEN REmOVED,mALE CL 51 mm, CW 42 mm (MZUSP 12898). Ab3–Ab4, AbDOmINAL SOmITES 3–4, RESpECTIVELy.ST7–ST8, THORACIC STERNITES 7–8, RESpECTIVELy.NOTE IN C THORACIC STERNITE 8 ExTENDING LATERALLy bEyOND STERNO-AbDOmINAL CAVITy, AND LEfT uNCOVERED LATERALLy by AbDOmEN AND THuS VISIbLE IN VENTRAL VIEW. Ep7, THORACIC EpISTERNITE 7. BLACk ARROWS (B, D) INDICATE OuTLINE Of THE AbDOmEN WHEN SEEN fOLDED bENEATH CEpHALOTHORAx.SCALE bARS:A, B, 5 mm; C, D, 10 Cm.

FIGURE3. Anamathia rissoana (ROux,1828), mALE,CL23 mm, CW 20 mm (USNM 152273).(A, B) HAbITuSDORSAL AND VENTRAL VIEWS, RESpECTIVELy. NOTE P2 muCH LONGER THAN P1. (C) VENTRAL VIEW Of CEpHALOTHORAx. BLACk ARROW IN (C) INDICATES THORACIC STERNITE 8 ExTENDING LATERALLy bEyOND STERNO-AbDOmINAL CAVITy, AND LEfT uNCOVERED LATERALLy by AbDOmEN. (D) DETAIL Of CEpHALOTHORAx ANTERIOR REGION IN VENTRAL VIEW. BLACk ARROW IN (D) INDICATES ANTEROLATERAL ANGLE Of buCCAL fRAmE pROTRuDED INTO STRONG,TRIANGuLAR LObE.ALSO NOTE IN (D) ANTENNAL SEGmENT 2+3 WITHOuT SpINES (WHITE ARROW).SCALE bARS:A, B 20 mm; C, D 10 mm.