Otus mauli, Rando, Juan Carlos, Pieper, Harald, Alcover, Josep Antoni & Olson, Storrs L., 2012

Rando, Juan Carlos, Pieper, Harald, Alcover, Josep Antoni & Olson, Storrs L., 2012, A new species of extinct fossil scops owl (Aves: Strigiformes: Strigidae: Otus) from the Archipelago of Madeira (North Atlantic Ocean), Zootaxa 3182, pp. 29-42 : 32-36

Otus mauli , new species

( Figs. 2 and 3 )

Holotype: Complete right tarsometatarsus ( MMF 41628; collected 11 April 1984; see Fig. 3 C).

Type locality: Ponta de São Lourenço (Madeira Island).

Horizon: Late Quaternary.

Status: Extinct.

Etymology: The new fossil owl species is named after Dr. honoris causa (1995) Günther Edmund Maul (7 May 1909 Frankfurt/M.– 28 Sept 1997 Funchal), who came to Madeira in October 1930. He worked first as a taxidermist in the Museu Municipal do Funchal (História Natural) and was later (1940–1981) its director. He was the leading expert on the Madeiran fauna in general, and especially on marine fishes. The majority of his publications (beginning in 1945) were listed by Wilhelm (2009). Wilhelm (2002 a, b) and Biscoito (1997) have provided obituaries.

Paratypes (locality and dates of collection are included): Madeira (Ponta de São Lourenço): MMF 41629, distal half of a right humerus with damaged distal end (Sep 1986); MMF 41630, distal part of a right ulna with damaged distal end (Sep 1986); MMF 41631, distal half of a right tibiotarsus with damaged distal end (Sep 1986); MMF 41632, almost complete right coracoid with the processus procoracoideus slightly broken (11 Apr 1984; Fig. 2 E); MMF 41633, distal half of a left humerus with a damaged end (11 Apr 1984; Fig. 2 A); MMF 41634, complete left tarsometatarsus (11 Apr 1984); MMF 41635, distal two-thirds of a left tarsometatarsus with damaged trochleae (19 Apr 1984); MMF 41636, proximal half of a left radius with the arcus origo musculi extensor longus digiti major broken (8 Apr 1984; Fig. 2 C); MMF 41637, distal half of a right femur (Sep 1988); MMF 41638, almost complete right femur, slightly eroded around the impressio musculi obturatorius (9 Sep 1985; Fig. 3 A); MMF 41639, diaphysis of a right femur (Sep 1986); DZUL 3054, proximal two-thirds of a right femur, with some damage at the end (Sep 1988); MMF 41640, almost complete left ulna, with the olecranon slightly broken and the condylus ventralis ulnae broken (Sep 1990; Fig. 2 B); MMF 41641, almost complete left tibiotarsus with the condylus medialis only slightly eroded (Sep1990; Fig. 3 B); MMF 41642, distal part of a right humerus with a damaged distal end (Sep 1990); DZUL 3055, right tarsometatarsus, without trochlea metatarsi II (May 1992); MMF 41643, proximal half of a left carpometacarpus (May 1992; Fig. 2 D); MMF 41644, fragment of diaphysis of a left ulna (Sep 1994); MMF 41645, medial fragment of a right humerus (Sep 1994).

Common name proposed: Madeiran Scops Owl

Diagnosis: A species of Otus with forelimb elements about the same size as those of O. scops , but with relatively much longer and more slender hindlimb bones.

Remarks: This species appears to be closely related to O. scops because of the similar morphology of: processus procoracoideus and processus acrocoracoideus of the coracoid; acromial part of the scapula, including the margo dorsalis scapularis; both epiphyses of the ulna, femur, tibiotarsus and tarsometatarsus, with its characteristic central trochlea shape.

Description. Forelimb bones of O. mauli are very similar in size and morphology to those of O. scops , its closest living relative ( Fig. 2 and Table 1 ). However, the hindlimb bones of both species are very different in size and proportions ( Fig. 3 ). The total leg length (femur+tibiotarsus+tarsometatarsus) is 20.5% greater in the new species. The percentage of difference is not the same for each bone, being 12.92 % (33.2 mm in Otus mauli vs. 29.4 mm in O. scops on average) for the femur; 19.05% (55.0 mm vs. 46.2 mm) for the tibiotarsus; and 32.01% (33.4 mm vs. 25.3 mm) for the tarsometatarsus ( Fig. 4 ; Table 1 ). These percentages indicate that the relative proportions of leg bones in O. scops and O. mauli are different ( Tables 2 and 3 ).

We estimated the weight of O. mauli to be c. 152 g (n = 1) through the Olmos et al. (1996) approach and c. 174 g (n = 2) through the Campbell and Marcus (1992) approach. The weight obtained from the femur length regression for O. scops is 107± 10 g (n = 25), the calculated range obtained with the same method (82–130 g) being close to the observed range for this species (64–135 g; Dunning 2008), while the weight obtained from the femur perimeter for O. scops ranges between 90 and 148 g (i.e., larger than the observed range). Although we should assume that they are overestimates of the weight of O. mauli , due to the similar size of the pectoral girdle of both species, our results seem to indicate that O. mauli probably had relatively weak powers of flight ( Fig. 5 ).

The PCA analysis performed with leg bone proportions (data from Tables 3 and 4) captured two principal components explaining 99.9% of total variance ( Fig. 6 ). Of this total, 61.8% is explained by PC1 which shows a high positive weighting for tarsometatarsus length and a high negative weighting for femur length. The PC2 explained 38.1% of variance that measured tibiotarsus length.

Madeira Sicily Crete Corse Mauritius

O. mauli A. trinacriae A. cretensis A. angelis M. sauzieri

% % % % % continued.

Rodrigues Oahu Molokai Maui M. murivorus G. o r i o n G. geleches G. erdmani

% % % % F 52.0 30.95 57.0 25.54 64.1 24.6 54.7 24.64 Tbt 72.5 43.15 100.5 45.03 116.0 44.51 98.0 44.14 Tmt 43.5 25.89 65.7 29.93 80.5 30.89 69.3 31.22 Tot 168.0 223.2 260.0 222.0 Em 567 742 1045 687

Figures

FIGURE 2. Comparison of wing bones of Otus mauli n. sp. (A – E) from Madeira island and O. scops, IMEDEA 2205 (A`– E`). (A, MMF 41633, A`) humeri, caudal view; (B, MMF 41640, B`) ulnae, ventral view; (C, MMF 41636, C`) radii, lateral view; (D, MMF 41643, D`) carpometacarpi, ventral view; (E, MMF 41632, E`) coracoid, ventral view. Scale = 2 cm.

FIGURE 3. Comparison of leg bones of Otus mauli n. sp. (A – C) from Madeira main island and O. scops, IMEDEA 2205 (A`– C`). (A, MMF 41638, A`) femora, caudal view; (B, MMF 41641, B`) tibiotarsi, cranial view; and (C, MMF 41628, holotype, C`) tarsometatarsi, dorsal view. Scale = 2 cm.

FIGURE 4. Leg bone lengths (mean ± standard error in mm of femur, tibiotarsus and tarsometatarsus) of O. mauli n. sp. (squares) and O. scops (circles). The percentages of difference in mean length [%] between both species are also shown.

FIGURE 5. Left. Reconstruction of Otus mauli n. sp. (Madeiran Scops Owl). Right. Compared sketches of Otus scops and Otus mauli n. sp. Art by Pau Oliver.

FIGURE 6. PCA plot for the two principal components obtained from leg bones (femur, tibiotarsus and tarsometatarsus) proportions of existing scops owls (genus Otus, squares), related species and other insular extinct owls (†). Data from Tables 2 and 3. 1: Otus scops; 2: O. mauli n. sp.; 3: O. nudipes; 4: O. petersoni Fitzpatrick and O’Neill; 5: O. watsonii (Cassin); 6: O. choliba (Vieillot); 7: O. atricapillus; 8: O. trichopsis; 9: O. clarkii; 10: O. kennicottii (Elliot); 11: O. asio (Linnaeus); 12: O. megalotis (Walden 1875); 13: O. bakkamoena Pennant; 14: O. magicus (Müller); 15: O. elegans (Cassin); 16: Gymnoglaux lawrencii; 17: Ptilopsis leucotis (Temminck); 18: Athene trinacriae; 19: A. cretensis; 20: A. angelis Mourer-Chauviré et al. 1997; 21: Mascarenotus sauzieri; 22: M. murivorus Mourer-Chauviré et al.; 23: Grallistrix orion; 24: G. geleches; 25: G. erdmani.

Tables

TABLE 1. Measurements of Otus mauli n. sp. and O. scops: sample size, mean length ± standard error (mm), and range. Measurements as in Campbell and Bocheński (2010).

Measurements	Otus mauli n. sp.	Otus scops
Coracoid
Length (A)	(1) 20.5	(25) 20.9±0.6 [19.6–22]
Depth of acrocoracoid (B)	(1) 2.5	(25) 2.3±0.2 [2–2.8]
Width of acrocoracoid (C)	(1) 3.3	(25) 3.5±0.2 [3.3–4.1]
Width of shaft at procoracoid (D)	(1) 3.7	(25) 4.0±0.2 [3.6–4.3]
Scapula
Length fac. artic. humeralis (B)	(1) 2.5	(25) 2.8±0.1 [2.5–3.0]
Width fac. artic. humeralis (C)	(1) 2.3	(25) 2.3±0.2 [2.1–2.7]
Humerus
Distal width (C)	(1) 7.4	(25) 7.5±0.2 [7.0–7.9]
Ulna
Proximal width (B)	(1) 4.8	(24) 4.8±0.2 [4.5–5.1]
Proximal depth (C)	(1) 3.9	(25) 3.9±0.2 [3.5–4.4]
Width of condylus dorsalis (D)	(1) 3.5	(25) 3.6±0.2 [3.2–4.0]
Femur
Length (A)	(1) 33.2	(25) 29.4±1.0 [26.9–31.5]
Proximal width (B)	(1) 6.3	(25) 5.4±0.2 [5.0–5.8]
Width at mid-shaft (C)	(2) 2.8±0.1 [2.8–2.9]	(25) 2.4±0.1 [2.2–2.7]
Depth at mid-shaft (D)	(2) 2.9±0.1 [2.9–3.0]	(25) 2.4±0.1 [2.0–2.7]
Distal width (E)	(2) 6.1±0.05 [6.1–6.2]	(25) 5.5±0.2 [5.2–5.9]
Distal depth (F)	(2) 5.3±0.05 [5.3–5.3]	(25) 4.5±0.2 [4.2–4.9]
Tibiotarsus
Total length (A)	(1) 55.0	(24) 46.2±1.6 [43.0–49.3]
Proximal width (B)	(1) 5.0	(25) 4.7±0.3 [4.3–5.1]
Proximal depth (C)	(1) 6.0	(25) 5.3±0.3 [4.5–5.8]
Width at mid-shaft (D)	(2) 2,4±0.1 [2.3–2.5]	(25) 2.2±0.2 [1.9–2.6]
Distal width (E)	(1) 5.4	(25) 5.2±0.2 [4.9–5.6]
Condylus lateralis depth (F)	(1) 4.4	(25) 4.2±0.2 [3.9–4.7]
Condylus medialis depth (G)	(1) 4.4	(25) 4.1±0.2 [3.8–4.5]
Tarsometatarsus
Total length (A)	(3) 33.4±0.5 [33.8–32.8]	(25) 25.3±1.6 [20.2–27.4]
Proximal width (B)	(3) 5.4±0.2 [5.2–5.6]	(25) 5.1±0.2 [4.7–5.3]
Hypotarsus length (C)	(1) 2.3	(25) 2.5±0.3 [1.9–3.1]
Hypotarsus width (D)	(1) 1.3	(25) 1.4±0.3 [1.2–1.7]
Minimum shaft width (E)	(4) 2.4±0.1 [2.3–2.4]	(25) 2.4±0.2 [2.1–2.7]
Distal width (F)	(2) 5.6±0.1 [5.5–5.7]	(25) 5.5±0.3 [5.1–5.9]

TABLE 2. Mean length (in mm) and proportions (%) of leg bones (F: femur; Tbt: tibiotarsus; Tmt: tarsometatarsus) to total leg bone length (femur + tibiotarsus + tarsometatarsus) (Tot), and estimated weight (Em; in g) from mean femur length (using the approach of Olmos et al. 1996) for extinct insular owl species: Otus mauli from Madeira (this paper); Athene trinacriae from Sicily (Pavia & Mourer-Chauviré 2002); A. cretensis from Crete (Weesie 1982); A. angelis from Corsica (Mourer-Chauviré et al. 1997); Mascarenotus sauzieri and M. murivorus from Mauritius and Rodrigues (Mourer-Chauviré et al. 1994); Grallistrix orion, G. g e l e c h e s and G. e rd m a n i from Oahu, Molokai and Maui (Hawaii) (Olson & James 1991).

F 33.2	27.27	40.7	27.55	42.5	28.29	47.2	31.09	55.4	27.54
Tbt 55.0	45.24	66.1	44.75	65.4	43.54	65.2	42.95	85.2	42.29
Tmt 33.4	27.49	40.9	27.69	42.3	28.16	39.4	25.95	60.8	30.17
Tot 121.6		147.7		150.2		151.8		201.4
Em 152		277		314		427		684