Equus germanicus Nehring, 1884

Fourvel, Jean-Baptiste, Fosse, Philippe, Fernandez, Philippe & Antoine, Pierre-Olivier, 2015, Large mammals of Fouvent-Saint-Andoche (Haute-Saône, France): a glimpse into a Late Pleistocene hyena den, Geodiversitas 37 (2), pp. 237-266 : 250-256

Equus germanicus Nehring, 1884

MATERIAL EXAMINED — NISP =922; MNI =62

1842 sample. — 1 palate; 1 right I1; 1 left I1; 1 right I2; 1 left I2; 1 right I3; 1 left I3; 1 right P2; 1 left P2; 2 right P3-4; 2 right M1-2; 2 left M1-2; 1 right M2; 1 left M3; 1 left d2; 2 right p2; 1 left p2; 3 left p3-4; 1 left p4; 1 right m1-2; 2 left m1-2; 1 left m3; 3 tooth fragments; 1 cervical vertebra; 1 right scapula; 1 left radio-ulna; 1 right metacarpal; 1 left metacarpal; 1 left innominate; 1 right tibia; 1 left pathological cuneiform and scaphoid; 1 right talus; 2 left tali; 2 left calcanei; 1 right metatarsal; 1 metatarsal; 1 vestigial metapodial; 2 first phalanges; 2 second phalanges.

1989-1992 sample: 3 left DI; 8 right D2; 8 left D2; 1 right D3; 13 right D3-4; 16 left D3-4; 1 right I1; 1 left I1; 1 I1/; 1 right I1-2; 1 right I2; 1 I3; 9 upper canines; 33 upper tooth fragments; 25 right P2; 23 left P2; 53 right P3-4; 60 left P3-4; 1 left M1; 94 right M1-2; 84 left M1-2; 3 M1-2; 34 right M3; 30 left M3; 1 mandible; 4 right di; 1 left di; 2 di; 6 right d2; 5 left d2; 2 left d3; 10 right d3-4; 4 left d3-4; 3 right d4; 5 left d4; 1 left lower deciduous tooth; 5 right i1; 5 left i1; 2 right i1-2; 2 left i1-2; 1 left i2; 1 right i2-3; 1 right i3; 16 right p2; 18 left p2; 28 right p3-4; 37 left p3-4; 1 left p3; 1 left p4; 1 right m1; 25 right m1- 2; 46 left m1-2; 4 right m2; 4 left m2; 22 right m3; 21 left m3; 11 lower tooth fragments; 1 pisiform; 1 right scaphoid; 1 left scaphoid; 1 right metacarpal; 1 right tibia; 1 tibia; 2 fibulae; 4 vestigial metapodials; 4 third phalanges; 3 sesamoids; 41 cheek tooth fragments; 14 incisor fragments.

DESCRIPTION

Because Equus caballus Linnaeus, 1758 includes wild and domestic caballine forms that may belong to several distinct lineages, we will not use here sub-specific rank but the binomen Equus germanicus . Morphometric data of the horse of Fouvent have not been described so far. Only an archaeozoologicaltaphonomical study was recently undertaken ( Fourvel et al. 2014) as well as horse population dynamics study analysis on the basis of dental crown heights ( Fernandez et al. 2006). A part of this dental material is presented here.

E. germanicus was recognized for the first time at Remagen ( Germany) and in many European sites ( Guadelli 1987; Fernandez 2006). The phylogeny of this species is not yet conclusively established and among different scenarios it could have derived from Equus taubachensis ( Eisenmann 1991; Eisenmann & David 1994), in spite of strong affinities with Equus steinheimensis von Reichenau, 1915 ( Prat 1968) . Equus germanicus is mainly represented in the early Late Pleistocene ( Prat 1968; Mourer-Chauviré 1980; Guadelli 1987; Eisenmann 1991; Armand 1998). It was replaced during the OIS3 by Equus gallicus Prat, 1968 , a robust but rather small-sized horse determined at Solutré (Saône-et-Loire), with longer protocones ( Prat 1968). Radiocarbon dates for E. c. gallicus were recently provided in southeastern France in Coulet des Roches and in the aven des Planes (Vaucluse). They are still present in these two sites at respectively 13.090±70 BP and 13.360±80 BP (Crégut-Bonnoure et al. 2014). According to Eisenmann (1991), E. gallicus reported in many French localities, could be a small form of E. germanicus . At Bize (Aude, France), a period of transition between E. germanicus and E. gallicus could be placed around c. 33 ka BP (Patou- Mathis 1994). A radiocarbon age of c. 35 ka is cautiously given at Camiac (Gironde, France; Guadelli 1987), while an age by thermoluminescence around 43 ka could be retained in the layer 6a of the Station Amont of La Quina (Charente, France; Armand 1998). The species E. caballus aff. germanicus was also recognized in Provence at the end of the OIS 2 in the Aven des Fourches II (Vaucluse, France; Brugal et al. 2001).

Lower teeth are under study and will be included later in a more complete analysis with post-cranial elements. For now, 283 upper cheek teeth have been studied ( Table 9). In this table, teeth are compared to a reference dataset of Pleistocene equids. For each measurement the number of teeth, minimum and maximum values, mean and confidence interval at 95% and standard deviation are given. The morphometrical distinction between ranks of premolars and molars (e.g., P3-P4 and M1-M2) is usually difficult or impossible with isolated teeth. Accordingly, we have chosen not to distinguish P3 from P4 and M1 from M 2 in order to compare the sample of Fouvent to a larger number of cheek teeth from literature.

As a first step, we wanted to know if the cohorts of horses from the different levels of Fouvent could be considered as coming from the same species. Thus, we grouped the stratigraphic units (e.g., Ab, Ba, C2...) in three levels namely A, B and C. Dental remains without stratigraphic location were excluded, as well as few teeth from the levels E and E9. We compared the Protocone Index using the Kruskal-Wallis test of one-way analysis of variance by ranks detailed previously. The analysis clearly indicates that there was no statistically significant difference between levels A, B, and C (α =0.05). Thus, dental material from those levels can be considered as originating from the same demographic/evolutionary unit, which is confirmed by the lack of differences in pairs of Dunn (1964) ( Table 10). The method of Dunn (1964) compares the mean of the ranks, the latter being those used in the calculation of k according a normal asymptotic distribution for the standardized difference of the average of the ranks.

The dimensions of most upper teeth of Fouvent match the variation range of both E. germanicus and E. gallicus ( Table 9). This is also the case in the upper part of the sequence of La Quina (Charente, France)which hosted the two species and made impossible their distinction based on their dimensions ( Armand1998). Here, we propose a new quantitative approach using biometric data, sourced from Eisenmann’s (1991) overview. Despite the phylogenetic uncertainties highlighted by her, all the caballine equids from Europe during the middle and late Pleistocene are carefully and methodically described in her analysis. The only difference with Eisenmann (1991) that we made here is that we consider as valid the well known species E. gallicus represented in France at Solutré ( Prat 1968), Jaurens (Mourer-Chauviré 1980), Camiac ( Guadelli 1987), or La Quina ( Armand 1998). The dataset of Eisenmann (1991) allowed us to calculate confidence intervals for lengths of upper teeth (except for P2 and M3, unavailable) and their protocone (CI with α =0.05). From a methodological point of view, the normality was tested using the Shapiro-Wilk test. For each measurement following a normal distribution, the confidence interval on the mean was given using the basic t-test of Student with the software R (2.14.0; t.test function).For the measurements which did not satisfy the conditions of normality, the confidence interval we derived was estimated from the theoretical median (wilcox.test function in R). Results indicate that intervals associated to Würmian species are well individualized from those related to ante-Würmian

A B C D E

F G H

equids. They only overlap on measurements which include the protocone length. Table 11 also shows that dimensions of the upper teeth of Fouvent are systematically associated to Würmian horses. This is confirmed by the occlusal protocone index of molars and premolars, which is always comprised between 114 and 126 for Würmian species (119.6 in Fouvent) and always lower than 114 for older equids, with the exception of Equus chosaricus Gromova, 1949 (114.1; Table 12).

To identify the horse of Fouvent at species level through dental measurements, we used the routine package knn.cv from R software (version 2.13.2). The program corresponds to one of the more efficient non-parametric methods for

Protocone index of

M1M2 / Protocone

Localities and/or species index of P3P4

Montoussé ( Equus mosbachensis ) 103.4

Pech-de-l’azé (niveau 9) 104.8 species Equus Tilloux Caune mosbachensis de l’Arago ( Equus chosaricus ) 108.4 108.3 109 horse localities Equus Equus Ehringsdorf missi taubachensis 109.5 109.6 109.7 Antewürmian and La Bau Equus Equus Biache-Saint-Vaast Micoque de piveteaui achenheimensis l’Aubesier (IJ) 109.8 111.8 110.6 112.5 111.6

Bau de l’Aubesier (H) 113.8

Equus chosaricus 114.1

Kniegrotte 114 species La Equus Bourgeois-Delaunay Chaise gallicus (Aurignacien (niveau 1) 4) 116.9 116.7 114.9 horse localities Grotte Bourgeois-Delaunay St-Germain-la-Rivière des fées (niveau 9) 117.5 118.2 117.3 Würmian and Fouvent Gavaudin Combe-Grenal 119.6 118.4 121.5

Pair-non-Pair 121.8

Equus germanicus 126.3

data classification in data mining: the so-called k-Nearest Neighbors (or k-NN for short; see details of the method in Mathieu-Dupas 2010). When there is little or no prior knowledge about the distribution of the original data, the rationale consists of finding among the predefined training samples (e.g., measurements of well known species) the closest distances of the new points that may be assigned to the original data. In this study, we applied the Euclidean distance, which is most commonly used. As an example, for a data point x of Fouvent, we computed the distance between x and all the data points from the training samples, in order to attribute the species determined by the nearest points of x according to k. This number k, usually an odd number, ranks the nearest neighbors from the training data. It determines the species to be assigned on the base of the majority vote using cross validation. When k is small (e.g., k =1), it improves the power of association even if noise may somewhat affect the results. However, when k increases it is less sensitive to noise and makes the borders of the classes less distinct but necessarily requires large training samples (Mathieu-Dupas 2010). Table 13 shows unambiguously and whatever k is, that the nearest species for the ratio of protocone length to occlusal length of M1M2 [M-pl/M-ol] is always E. germanicus . The same is true for the ratio of the length of protocone to the occlusal average length of P3P4M1M2 [PM-pl/PM-ol], except for an isolated case (k =7) which is associated to Equus antunesi Cardoso & Eisenmann, 1989 . Nevertheless, E. steinheimensis appears for the ratio of the length of the protocone to the occlusal length of P3P4 [P-pl/P-ol], as the closest species except for k =9, k =13 and k =14 which are attributed once again with E. germanicus . However, the dental morphology of E. steinheimensis allows undoubtedly excluding such an assignment because caballoid and stenoid characters are not observed at Fouvent, contrary to what occurs at Châtillon-Saint-Jean (Drôme, France; Mourer- Chauviré 1972). At Fouvent, dentition shows styles with splits on the premolars, molars with simple parastyle and mesostyle, concave interstylar surfaces, and bilobed protocones. Even so, the proximity between E. steinheimensis and E. germanicus is not trivial and refers to the hypothesis of a possible phylogenetic relationship, as mentioned by Prat (1968: 520). Finally, our analysis does not either reveal a possible association between the horse of Fouvent and the more evolved E. gallicus .

At the end of this study, it appears that dental morphometry, coupled with high resolution analytical tools can account for evolutionary stages of Pleistocene horses. We have shown that the horse of Fouvent was associated to the typical species E. germanicus but did not yet reach the evolutionary stage as observed in E. gallicus . In conclusion, in an anagenetic perspective, it is quite reasonable to consider that the deposition E. germanicus of Fouvent is probably associated to the time interval from the very end of OIS 4 to the end of OIS 3.

Suborder CERATOMORPHA Wood, 1937 Family RHINOCEROTIDAE Gray, 1821 Subfamily RHINOCEROTINAE Gray, 1821 Genus Coelodonta Bronn, 1758