The earliest known fisher (Mustelidae), a new species from the Rattlesnake Formation of Oregon

Figures & data

FIGURE 1 Map showing the Sheep Rock unit of John Day Fossil Beds National Monument, Grant County, Oregon. The area where the specimen described here was found is indicated by an asterisk.

FIGURE 2 Holotype of Pekania occulta (JODA 15214) from the Rattlesnake Formation, Oregon. Specimen consists of a left maxilla with partial P3, P4, and M1, and partial left P2 and right I3. A, left lateral view; B, occlusal view. Scale bar equals 1 cm

FIGURE 3 Stereophotograph of grayscale cast of Pekania occulta holotype (JODA 15214). Scale bar equals 1 cm.

TABLE 1 Dental measurements (in mm) of Pekania and Martes species.

			I3		P2	P3	P4			M1
Species	Specimen no.	Locality	L	W	W	W	L	Wpro	Wmet	Lext	Lint	W
Pekania occulta	JODA 15214	Oregon	4.8	2.4	3.0	4.1	13.3	8.8	5.3	5.6	8.5	12.8
P. pennanti	Mean (♂, n = 12)	Various	4.1	2.4	3.0	3.4	12.2	7.4	4.6	6.2	7.4	10.9
	Min.		3.8	2.1	2.8	3.3	11.7	6.8	4.3	5.8	7.0	10.1
	Max.		4.4	2.7	3.2	3.6	13.4	7.9	4.9	6.5	7.8	11.5
	Mean (♀, n = 10)		3.6	2.0	2.6	3.0	10.7	6.5	3.7	5.3	6.1	9.2
	Min.		3.3	1.6	2.0	2.8	10.0	5.8	3.3	4.9	5.5	8.4
	Max.		3.8	2.1	3.0	3.4	11.1	7.2	3.9	5.9	6.4	9.5
P. diluviana	USNM 8010^a	Maryland					10.2	6.0	3.9	5.0	6.0	9.5
P.	PMU 3793	China	3.2	1.9	2.0	2.9	11.0	6.4	4.0	5.7	6.5	10.4
palaeosinensis	Min.^b				1.9	2.6	9.0	4.6			5.2	8.5
	Max.^b				2.5	3.7	11.5	6.7			7.6	10.9
Martes americana	Mean (♂, n = 3)		2.3	1.8	2.1	2.6	9.0	5.7	3.4	4.3	6.5	9.3
M. martes	LACM 74508		2.7	1.7	2.8	3.8	9.3	6.1	3.4	4.7	7.8	9.6
M. flavigula	LACM 8229		2.5	2.1	2.6	3.4	10.1	6.4	3.5	4.0	5.3	9.6
Abbreviations: L, anteroposterior length; W, transverse width; pro, at protocone; met, at metacone; ext, external lobe; int, internal lobe. Detailed definitions of dental measurements are provided in Appendix 1.
^aGidley and Gazin (1933); ^bZdansky (1924).

APPENDIX 1 Definitions of dental measurements presented in Table 1

Measurement	Definition
I3 length (I3L)	Maximum anteroposterior diameter of upper third incisor.
I3 width (I3W)	Maximum transverse diameter of upper third incisor.
P2 width (P2W)	Maximum transverse diameter of upper second premolar.
P3 width (P3W)	Maximum transverse diameter of upper third premolar.
P4 length (P4L)	Maximum anteroposterior diameter of upper fourth premolar, taken from the parastyle to the metastyle.
P4 width at protocone (P4Wpro)	Maximum transverse diameter of upper fourth premolar at the protocone.
P4 width at metacone (P4Wmet)	Maximum transverse diameter of upper fourth premolar at the metacone.
M1 length (M1Lext)	Maximum anteroposterior diameter of upper first molar, taken along the labial border of the tooth.
M1 length (M1Lint)	Maximum anteroposterior diameter of upper first molar, taken along the lingual border of the tooth.
M1 width (M1W)	Maximum transverse diameter of upper first molar, taken from the labial (hypoconal) cingulum to the lingual border between the paracone and metacone.

Zdansky , O. 1924 . Jungtertiäre Carnivoren Chinas . Palaeontologia Sinica, Series C , 2 ( 1 ) : 1 – 149 .

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