Rallus carvaoensis, Alcover, Josep Antoni, Pieper, Harald, Pereira, Fernando & Rando, Juan Carlos, 2015

Alcover, Josep Antoni, Pieper, Harald, Pereira, Fernando & Rando, Juan Carlos, 2015, Five new extinct species of rails (Aves: Gruiformes: Rallidae) from the Macaronesian Islands (North Atlantic Ocean), Zootaxa 4057 (2), pp. 151-190 : 162-163

Rallus carvaoensis , new species

São Miguel rail

[ Figures 5 , 8 B–E, 9A, 10C, 11C, 12B, 13A, 15C, 16C, 17C] Artistic reconstruction: Figure 23

Holotype: MCMa 1801.013, partial skeleton: man, pmx frag, L scap frag, R scap, LR hum, L uln prox, R uln, R cmc frag, pel frag, L fem, R dis fem, LR tbt, LR tmt, quad, 20 vers 7 ped pha.

Measurements of the holotype (right, left, in mm): Humerus—length: 28.5, 28.6; proximal width: 6.2, 6.3; minimum shaft width: 1.9, 1.9; distal width: 4.1, 4.1. Ulna—minimum shaft width: 1.2, 1.3; distal width: 2.4, -. Femur—length: -, 36.0; minimum shaft width: ~2.0, ~2.0; distal width: ~5.0, ~7.0. Tibiotarsus—minimum shaft width: 2.5, 2.5; distal width: 4.6, 4.6. Tarsometatarsus—length: -, 31.7; minimum shaft width: 2.6, 2.5; distal width: -, 5.5. Scapula—length: 25.6, -; proximal width: 3.6, -.

Type locality and collection information: Gruta do Carvão, São Miguel; all the material of R. carvaoensis n. sp. was collected in this cave in August 2011 by JCR, MT, and JAA.

Paratypes: IMEDEA 104068, partial skeleton (sku frag, man frags, cor frag, pel frag, fem frag, L tbt and dis R tbt, R tmt and dis L tmt, 12 verts, 5 ped phas); MCMa 1802.013, partial skeleton (sku frag, pmx frags, R tbt frags, LR tmt frags, verts, ped phas); MCMa 1803.013, partial skeleton (man frags, pmx frags, LR tbt frags, tmt frags, 9 ped phas); DZUL 3183, partial skeleton (sku frags, pel frags, R fem and prox L fem, R tbt and prox L tbt, tmt and dis tmt); DZUL 3184, partial skeleton (man frags, pmx frags, cor, L hum, pel frag, LR fem frags, LR tbt frags, LR tmt frags, 18 vers, pha); MCMa 1804.013, partial skeleton (sku frags, man frags, pmx frags, R fem frag, R tbt frag, R tmt and dis L tmt, 6 ped phas); MCMa 1805.013, partial skeleton (sku frags, man frag, ste frag, R cor and L cor frag, hum frag, uln frag, rad frag, LR cmc, R fem and L fem frag, LR tbt, pel frag, 10 vers); IMEDEA 104069, partial skeleton (pmx frags, R hum, vers); MCMa 1806.013, partial skeleton (tbt frags, tmt frag, 5 vers); MCMa 1807.013, partial skeleton (man frags, pmx frags, L tmt and R tmt frag, 1 ped pha); MCMa 1808.013, partial skeleton (man frag, pmx frag, L cor, L hum and dis R hum, R uln frag, LR tbt, 1 ped pha); MCMa 1809.013, partial skeleton (sku frag, man frags, R fem and L sha fem, tbt frag, tmt frag, 6 vers); MCMa 1810.013, partial skeleton (LR cor frags, sca frag, L hum frag, femur frag, tbt frag, 10 vers); MCMa 1811.013, partial skeleton (fem frag, tbt frags, pel frags, 2 vers); MCMa 1812.013, partial skeleton (man frags, pmx frags, L hum and R hum frag, L fem, tbt frags, L tmt, 3 vers); MCMa 1813.013, partial skeleton (man frags, uln frag, R tbt frag, L tmt, 3 ped phas); MCMa 1814.013, partial skeleton (LR tbt frag); MCMa 1815.013, partial skeleton (L tbt fra, LR tmt frags).

Measurements of paratypes: See Table 1.

Age: Probably Holocene-Recent.

Diagnosis. A species of Rallus of small body size and with very reduced wing bones ( Figures 11-13 ). The humerus has a reduced fossa pneumotricipitalis, a crista bicipitalis less expanded than in R. aquaticus , and a reduced and relatively flattened caput. The tibiotarsus, and especially the tarsometatarsus are very shortened compared to those of R. aquaticus , but relatively robust ( Figures 16 and 17 ). The corpus ossi premaxillaris is slightly more curved than in R. aquaticus ( Figure 8 ). All the bones are smaller than in R. aquaticus and larger than in R. minutus n. sp. The wing bones and the tarsometatarsus are smaller than those of R. lowei n. sp., R. adolfocaesaris n. sp. and R. montivagorum n. sp.

Etymology. From the type locality and only known site of this rail.

Figures

FIGURE 5. Bones of the associated skeleton of the holotype of Rallus carvaoensis n. sp. MCMa 1801.013. A, humeri (1, R, caudal view; 2, R, cranial view; 3, L, caudal view; 4, L, cranial view). B, R ulna (1, dorsolateral view, 2, ventral view). C, R carpometacarpus (1, ventral view; 2, dorsal view). D, premaxilla (lateral view), E L femur (1, caudal view; 2, cranial view), F, L tibiotarsus (1, cranial view; 2, caudal view). G L tarsometatarsus (1, dorsal view; 2, plantar view). Scale bar: 2 cm.

FIGURE 8. Skulls and premaxillae of Rallus spp. A, Rallus aquaticus IMEDEA 12474. B, Rallus carvaoensis n. sp. IMEDEA 104069. C, Rallus carvaoensis n. sp. MCMa 1801.013. D, Rallus carvaoensis n. sp. MCMa 1804.013. E, Rallus carvaoensis n. sp. MCMa 1812.013. F, Rallus montivagorum n. sp., DZUL 3185, (paratype). G, Rallus lowei n. sp., MMF 43421, (paratype). H, Rallus adolfocaesaris n. sp., MMF 43450, Porto (paratype). I, Rallus minutus n. sp., MCMa 1950.014. 1, dorsal view. 2, ventral view. 3, lateral view. Scale bar: 2 cm.

FIGURE 11. Humeri of Rallus spp. A, Rallus lowei n. sp., MMF 43414, L humerus (paratype). B, Rallus adolfocaesaris n. sp., MMF 43451, R humerus (specular image) (paratype). C, Rallus carvaoensis n. sp., MCMa 1801.013, R humerus (specular image). D, Rallus montivagorum n. sp., MCMa 1943.014,, R humerus (specular image). E, Rallus minutus n. sp. MCMa 1951.014. F, Rallus aquaticus, IMEDEA 12474, R humerus (specular image). 1, caudal view. 2, cranial view. Scale bar: 2 cm

FIGURE 12. Ulnae of Rallus spp., dorsal view. A, Rallus lowei n. sp., MMF 43415, R ulna (paratype). B, Rallus carvaoensis n. sp., MCMa 1801.013, R ulna. C, Rallus montivagorum n. sp., MCMa 1867.014, L ulna (specular image). D, Rallus minutus n. sp., MCMa 1950.014, L ulna (specular image). E, Rallus aquaticus, IMEDEA 12474, R ulna. Scale bar: 1 cm.

FIGURE 13. Carpometacarpi of Rallus spp. A, Rallus carvaoensis n. sp., MCMa 1805.013, R carpometacarpus. B, Rallus montivagorum n. sp., MCMa 1856.014, R carpometacarpus. C, Rallus minutus n. sp. MCMa 1950.014, L carpometacarpus (specular image). D, Rallus aquaticus IMEDEA 12474. R carpometacarpus. 1, ventral view. 2, dorsal view. Scale bar: 1 cm.

FIGURE 16. Tibiotarsi of Rallus spp. A, Rallus lowei n. sp., MMF 43426 / 43427, R tibiotarsus (paratype) (specular image). B, Rallus adolfocaesaris n. sp., MMF 43447, L tibiotarsus, (paratype). C, Rallus carvaoensis n. sp., IMEDEA 104068, L tibiotarsus. D, Rallus montivagorum n. sp., IMEDEA 104097, R tibiotarsus (specular image). E, Rallus minutus n. sp. MCMa 1951.014, R tibiotarsus (specular image). F, Rallus aquaticus, IMEDEA 12474, R tibiotarsus (specular image). 1, cranial view. 2, caudal view. Scale bar: 2 cm.

FIGURE 17. Tarsometatarsi of Rallus spp. A, Rallus lowei n. sp., MMF 43419, R tarsometatarsus (paratype). B, Rallus adolfocaesaris n. sp., MMF 43445, R tarsometatarsus (paratype). C, Rallus carvaoensis n. sp., IMEDEA 104068, R tarsometatarsus. D, Rallus montivagorum n. sp., MCMa 1949.014, R tarsometatarsus. E, Rallus minutus n. sp., MCMa 1951.014, R tarsometatarsus. F, Rallus aquaticus IMEDEA 12474, R tarsometatarsus. 1, dorsal view. 2, plantar view. Scale bar: 2 cm.

FIGURE 23. Artist reconstruction of the Rallus species described. Colours are speculative. Art: Pau Oliver.