Rallus montivagorum, 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 : 163-166

Rallus montivagorum , new species

Pico rail

[ Figures 6 , 8 F, 9B, 10B, 11D, 12C, 13B, 14B, 15D, 16D, 17D] Artistic reconstruction: Figure 23

Holotype: McMa 1831.014, associated skeleton: sku frag, man frags, ster frag, LR scap, R cor, R hum and L hum frags, L uln, L cmc, syn, LR fem, LR tbt, L tmt.

Measurements of holotype (in mm): Humerus—length 32.9, proximal width 6.7, minimum shaft width 2.2, distal width 4.7. Ulna—length: 25.8; proximal width: 3.1; proximal diameter: 2.9; minimum shaft width—2.0; distal width: 3.0. Carpometacarpus—length: 16.8; proximal width: 4.2; distal width: 2.4. Femur—length: 35.8; proximal width: 5.7; minimum shaft width: 2.5; distal width: 5.6. Tibiotarsus—total length: 55.0; medial length: 53.1; proximal width: 5.7; minimum shaft width: 2.4; distal width: 4.9. Tarsometatarsus—length: 33.3; proximal width: 5.1; minimum shaft width: 2.4; distal width: 5.0. Scapula—length: 29.0; proximal width: 4.5. Coracoid: length: 16.8. Cranial length (without the bill)—26.8; cranial width: 14.9; interorbitarium witdth: 3.7; cranial height: 15.3. Sternum—length of the manubrium: 29.8; smallest width: 5.6. Synsacrum—total length: 31.8; vertebral length: 28.9; cranial width: 11.7; smallest beadth: 7.1; antitrochantherian width: 14.1.

Type locality: Furna das Torres, Pico, collected 18 July 2013.

Known distribution: Pico, Central Azores.

Collectors: all the material obtained at Pico was collected in July 2013 by JCR, FP, JCI, EB and JAA.

Paratypes: Furna das Cabras, 17–19 July 2013: MCMa 1832.014, associated skeleton (sku frags, man frags, pmx frags, LR cor, R scap frag, LR hum, L uln, R cmc, pel frag, LR fem, LR tbt); MCMa 1833.014, associated skeleton (LR fem, L tbt frag, L tmt frag); MCMa 1834.014, associated skeleton (L cor, cmc frag, syn, LR fem, L tbt frags, tmt, ped phas); MCMa 1835.014, associated skeleton (man frag, ste frag, L scap frag, R hum and L hum frags, R uln and L uln frags, syn frags, L fem, tbt and tbt frags, ped phas); IMEDEA 104089, associated skeleton (ste frag, R cor, L hum and R hum frag, LR uln, syn frags, LR fem frags, LR tbt frags, LR tmt frags); MCMa 1836.014, associated skeleton (sku frags, man frags, LR fem, syn frag, tbt frag); MCMa 1837.014, associated skeleton (sku frag, syn frag, LR fem, R tbt frags, tmt frags); DZUL 3185, associated skeleton (sku, man frags, R scap, R cor, ste frag, LR hum frags, R uln frag, L cmc, syns frag, L fem, L tbt frag, L tmt and R dis tmt frag); MCMa 1838.014, associated bones (R fem and dis tbt); MCMa 1839.014, associated bones (pmx frag, L hum and R hum frag, L uln, LR cmc, 2 R fem, L fem and a R fem frag, R tbt frag, tmt frag); MCMa 1840.014, associated skeleton (man frags, pmx frag, L tbt); MCMa 1841.014, associated skeleton (man frags, pmx frag, R hum frag, L fem, LR tbt, LR tmt frags, ped pha); MCMa 1842.014, associated skeleton (sku frag, L cor, hum frag, L fem, tmt); MCMa 1843.014, associated skeleton (sku frag, L fem and sha R fem); MCMa 1844.014, associated skeleton (pmx frag, man frags, qua, ste frag, LR cor, R sca, R hum, syn frag, R fem and dis L fem, tbt frag); MCMa 1845.014, associated bones (sku frag, man frag, syn frag, 2 R fem, L tbt and R tbt frag, tmt); MCMa 1849.014, associated bones (sku frags, man frags, pmx frags, ste frags, 2 R hum, L hum, R cmc, LR fem and LR fem frag, 8 LR tbt, 5 LR tmt); MCMa 1940.014, associated bones (man frag, L cor, L hum frag, syn frag, LR fem and L fem frag, LR tbt frags, tmt, vers,); IMEDEA 104090, L cmc; MCMa 1850.014, L cmc; MCMa 1851.014, L cmc; MCMa 1852.014, L cmc; MCMa 1853.014, L cmc; MCMa 1854.014, L cmc; IMEDEA 104091, R cmc; MCMa 1941.014, R cmc; MCMa 1855.014, R cmc; MCMa 1856.014, R cmc; MCMa 1857.014, R cmc; MCMa 1858.014, R cmc; MCMa 1859.014, L hum; IMEDEA 104092, L hum; MCMa 1860.014, L hum; DZUL 3186, L hum; MCMa 1861.014, L hum; MCMa 1942.014, R hum; MCMa 1862.014, R hum; MCMa 1943.014, R hum; MCMa 1947.014, R hum frag; MCMa 1863.014, R hum; DZUL 3187, R hum; MCMa 1864.014, R hum; MCMa 1865.014, R hum; MCMa 1866.014, L uln; MCMa 1867.014, L uln; IMEDEA 104093, L uln; MCMa 1868.014, L uln; MCMa 1869.014, R uln; DZUL 3188, R uln; DZUL 3189, R uln; MCMa 1870.014, R uln; MCMa 1944.014, R uln; MCMa 1945.014, R uln; MCMa 1871.014, L fem; MCMa 1872.014, L fem; IMEDEA 104094, L fem; IMEDEA 104095, L fem; MCMa 1873.014, L fem; DZUL 3190, L fem; MCMa 1946.014, L fem; MCMa 1874.014, L fem; MCMa 1875.014, L fem; MCMa 1876.014, L fem; MCMa 1877.014, L fem; MCMa 1878.014, L fem; MCMa 1879.014, R fem; MCMa 1880.014, R fem; MCMa 1881.014, R fem; MCMa 1882.014, R fem; MCMa 1883.014, R fem; MCMa 1884.014, R fem; MCMa 1885.014, R fem; MCMa 1886.014, R fem; MCMa 1887.014, R fem; MCMa 1888.014, R fem; MCMa 1889.014, R fem; MCMa 1960.014, R fem frag; MCMa 1890.014, R fem; MCMa 1891.014, L tbt; MCMa 1892.014, L tbt; MCMa 1893.014, L tbt; MCMa 1894.014, L tbt; MCMa 1895.014, L tbt; MCMa 1896.014, L tbt; IMEDEA 104096, R tbt; MCMa 1897.014, R tbt; IMEDEA 104097, R tbt; MCMa 1898.014, R tbt; DZUL 3191, R tbt; MCMa 1899.014, R tbt; MCMa 1900.014, R tbt; DZUL 3192, R tbt; MCMa 1901.014, R tbt; MCMa 1948.014, R tbt; MCMa 1983.014, R tbt; MCMa 1985.014, R tbt; MCMa 1902.014, R sca; MCMa 1903.014, cranial part of R sca; MCMa 1904.014, cranial part of R sca; MCMa 1905.014, cranial part of R sca; MCMa 1906.014, cranial part of L sca; MCMa 1907.014, cranial part of L sca; MCMa 1908.014, cranial part of L sca; MCMa 1909.014, cranial part of L sca; MCMa 1910.014, L cor; MCMa 1911.014, L cor; MCMa 1912.014, L cor; MCMa 1913.014, L cor; MCMa 1914.014, L cor; MCMa 1915.014, L cor; MCMa 1916.014, L cor; MCMa 1917.014, cranial end of L cor; MCMa 1918.014, R cor; MCMa 1919.014, R cor; MCMa 1920.014, R cor; MCMa 1921.014, R cor; DZUL 3193, R tmt; MCMa 1949.014, R tmt; IMEDEA 104098, R tmt; IMEDEA 104099, R tmt; MCMa 1922.014, L tmt; MCMa 1923.014, L tmt; MCMa 1924.014, L tmt; MCMa 1925.014, tmt; MCMa 1926.014, tmt; MCMa 1927.014, tmt; MCMa 1928.014, tmt; MCMa 1929.014, tmt; MCMa 1930.014, tmt; MCMa 1931.014, tmt; MCMa 1932.014, sku; MCMa 1933.014, sku; MCMa 1934.014, sku; MCMa 1935.014, sku; MCMa 1984.014, sku frag; MCMa 1994.014, sku frag; MCMa 1995.014, sku frag; MCMa 1996.014, sku frag; MCMa 1936.014, ste; MCMa 1991.014, ste frag; MCMa 1992.014, ste frag; MCMa 1993.014, ste frag; MCMa 1937.014, syn; MCMa 1938.014, syn; MCMa 1939.014, syn; MCMa 1986.014, pmx frag; MCMa 1987.014, pmx frag; MCMa 1988.014, man frag; MCMa 1989.014, man frag; MCMa 1990.014, man frag.

Furna da Galinha, 21 July 2013: MCMa 1846.014, associated skeleton (man frag, tbt frag, tmt frag).

Furna do Frei Matias, 19 July 2013: MCMa 1847.014, associated bones (fem and dis fem);

Furna das Torres, Pico, 18 July 2013: MCMa 1848.014, associated skeleton (sku frags, man frags, qua, cor, sca, LR hum, LR uln, LR cmc, syn, LR fem, LR tbt, LR tmt, ped pha).

Age: Holocene-Recent. We obtained two AMS 14C dates at the Royal Institute for Cultural Heritage (Brussels) on bones of R. montivagorum n. sp.: RICH 21401 (Furna das Cabras sample, 1.10g of fragmented bones of an associated rail skeleton): 1487± 30 BP, 437–645 cal AD; and RICH 21396 (Furna das Torres sample, 2g of fragmented bones of an associated rail skeleton): 489±29 BP, 1405–1450 cal AD. The last date overlaps the timing of the Portuguese colonization, and shows the species overlapped with humans. It is probably very close to the time of the extinction of the species.

Diagnosis. A species of Rallus slightly smaller than R. aquaticus in overall size and with a reduced sternum ( Figure 10 ). The femur and tibiotarsus are only slightly smaller than those of R. aquaticus ( Figures 15 and 16 ), whereas the tarsometatarsus is about 36% shorter (see Figure 17 ). Rallus montivagorum has a longer coracoid, humerus, carpometacarpus ( Figures 9 to 11) and tarsometatarsus than R. carvaoensis n. sp. The ulna is longer than in R. lowei n. sp. ( Figure 12 ). The tarsometatarsi of both species are of similar length, but R. lowei is much stouter. Rallus montivagorum has a smaller and less robust humerus than R. adolfocaesaris n. sp., and while the tarsometatarsus of both species are similar in length, that of R. montivagorum sp. nov. is more gracile.

Etymology. The specific name is a latinization of the name of the Azorean society Os Montanheiros, who we honor here for their long-standing assistance in the palaeontological exploration of the caves of the central Azores.

Figures

FIGURE 6. Bones of the associated skeleton of the holotype of Rallus montivagorum n. sp. McMa 1831.014. A, skull (1, dorsal view, 2, ventral view, 3, lateral view). B, mandible. C, R coracoid (1, ventral view; 2, dorsal view). D, R scapula (1, lateral view; 2, internal view). E, sternum (1, lateral view; 2, dorsal view; 3, ventral view). F, R humerus (1, caudal view; 2, cranial view). G, L ulna (1, ventral view; 2, dorsal view). H, L carpometacarpus (1, ventral view; 2, dorsal view). I, R femur (1, cranial view; 2, caudal view). J, R tibiotarsus (1, cranial view; 2, caudal view). K, L tarsometatarsus (1, dorsal view; 2, plantar view). L, synsacrum (1, dorsal view; 2, ventral 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 9. Coracoidea of Rallus spp. A, Rallus carvaoensis n. sp., MCMa 1805.013, R coracoid (specular image). B, Rallus montivagorum n. sp., MCMa 1913.04, L coracoid. C, Rallus minutus n. sp., MCMa 1950.014, D, Rallus aquaticus IMEDEA 12474, R coracoid (specular image). 1, ventral view. 2, dorsal view. Scale bar: 1 cm.

FIGURE 10. Sterna of Rallus spp. A. Rallus aquaticus, IMEDEA 12474. B. Rallus montivagorum n. sp., MCMa 1831.014, Pico. C. Rallus carvaoensis n. sp., MCMa 1805.013. D. Rallus minutus n. sp., MCMa 1951.014. 1, ventral view. 2, dorsal view. 3, lateral 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 15. Femora of Rallus spp. A, Rallus lowei n. sp., MMF 43420, L femur (specular image), (paratype). B, Rallus adolfocaesaris n. sp., MMF 43453, R femur, (paratype). C, Rallus carvaoensis n. sp., DZUL 3183, R femur. D, Rallus montivagorum, MCMa 1880.014, R femur. E, Rallus minutus n. sp. MCMa 1954.014, R femur. F, Rallus aquaticus, IMEDEA 12474, L femur (specular image). 1, cranial view. 2, caudal view. Scale bar: 2 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.