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Figure 1. Map showing Chadronian and Orellan fossil localities (after Emry et al. 1987).
Figure 2. Correlation chart of Oligocene fossil localities (after Emry et al. 1987).
Figure 3. Idealized diagram of occlusal view of tooth showing points digitized and positions of accessory cusps.
Figure 4. Idealized diagram of lingual view of tooth showing points digitized and position of lingual accessory cusp.
Figure 5. Idealized diagram of lingual view of jaw showing points digitized.
Figure 6. Sample panels from database.
Figure 7. Diagram of jaw measurements in lingual view.
Anterior
Posterior
Figure 8. Diagram of tooth measurements in occlusal view.
Figure 9. Diagram of tooth measurements in lingual view.
Figure 10. Scatterplot of 486 M/2's from Toadstool Park.
Figure 11. Scatterplot of 717 M/2's from Munson Ranch.
Figure 12. Scatterplot of 59 M/2's from Geike Ranch.
Figure 13. Scatterplot of 161 M/2's from Lusk area.
Figure 14. Scatterplot of 115 M/2's from Douglas area.
Figure 15. Scatterplot of 47 M/2's from Chadron area.
Figure 16. Scatterplot of 127 M/2's from Slim Buttes.
Figure 17. Scatterplot of 59 M/2's from Little Badlands.
Figure 18. Scatterplot of 111 M/2's from Flagstaff Rim.
Figure 19. Histogram of canonical variable from the output of three pairwise discriminant analyses.
Figure 20. Mean tooth area of M/2 for 30 foot stratigraphic intervals at Toadstool Park and Munson Ranch, Sioux County, Nebraska. The sample size for each interval is shown in parentheses.
Figure 21. Mean value of labial accessory cusp for 30 foot stratigraphic intervals at Toadstool Park and Munson Ranch, Sioux County, Nebraska. The sample size for each interval is shown in parentheses.
Figure 22. Mean value of anterior medial accessory cusp for 30 foot stratigraphic intervals at Toadstool Park and Munson Ranch, Sioux County, Nebraska. The sample size for each interval is shown in parentheses.
Figure 23. Mean value of posterior medial accessory cusp for 30 foot stratigraphic intervals at Toadstool Park and Munson Ranch, Sioux County, Nebraska. The sample size for each interval is shown in parentheses.
Figure 24. Mean value of lingual accessory cusp for 30 foot stratigraphic intervals at Toadstool Park and Munson Ranch, Sioux County, Nebraska. The sample size for each interval is shown in parentheses.
Figure 25. Result of Cluster analysis using Ward method on standardized mean values of 27 groups of Ischyromys. Size is the first order distinguishing variable.
Figure 26. Two dimensional output of multidimensional scaling on 27 populations including absolute size.
Figure 27. Two dimensional output of multidimensional scaling on 27 populations excluding absolute size.
Figure 28. Result of Cluster analysis using Ward method on standardized mean values of 27 groups of Ischyromys after overall size was factored out.
Figure 29. Plot of mean values of the anterior and posterior angles between the tooth row and the ventral margin of the jaw.
Figure 30. Plot of mean values of the length of M/2 and M/3.
Figure 31. Plot of mean values of the length of M/2 and the length from the posterior valley mouth to the posterior end of the tooth on M/3.
Figure 32. Plot of mean values of angles made by the posterior and medial walls of the anterior lingual valleys vs. tooth size.
Figure 33. Plot of mean values of cusp heights divided by valley heights in lingual view vs. tooth size.
Figure 34. Phylogenetic tree showing possible relationships between species of Ischyromys and Titanotheriomys.
|-ISCHYROM.SPE-4588------------------------------------------------------------|
|Roll039.11 Frame 11 Field # 488-54G Acc. # Coll. # |
|Cat. # UNSM 05513 Coll. Carl Vondra and John A. Howe 1954 |
|Loc. #UNSM Sx-26 Material D L M/1-2 0 3 3 0 Taxon I. typus |
|Stratigraphy Orella A Section 53 Level +5 +/- 5|
|0-10 feet above upper purple-white layer |
|Ref. Notes |
|Comments °°°°|
|------------------------------------------------------------------------------|
Ú-ISCHYROM.LOC-520-------------------------------------------------------------¿
|Loc. # UCM 78075 Name Cameron Spring Lat. 42.47 Long. 107.33|
|Gas Hills, Wind River Basin |
|SE1/4, NW1/4, sec. 1, T32N, R90W |
|Map Gas Hills County Fremont State Wyoming |
|Group White River Form. Chadron Memb. Section76|
|Epoch Oligocene Age Chadronian Ref. °|
À------------------------------------------------------------------------------Ù
Ú-ISCHYROM.SEC-62--------------------------------------------------------------¿
|Section 54 ° Name Toadstool Park, Sioux County, Nebraska |
|Schultz and Stout 1955; Skinner section book 4:116-119 |
| |
À------------------------------------------------------------------------------Ù
Ú-ISCHYROM.JAW-4014------------------------------------------------------------¿
|Roll358.02 Jaw Measurements from basic MEASURE program |
| 1 11.54 2 10.40 3 8.33 4 8.19 5 4.41 6 6.03 7 45 8 50 9 1 |
|Ant. jaw Med. jaw Post. jaw depth Ant-Med Med-post A-M M-P Right|
| depth depth (line) (point) distance distance angle angle /Left|
| |
| Jaw measurements calculated from above data |
|10 25 |
|Jaw curve |
À------------------------------------------------------------------------------Ù
Ú-ISCHYROM.P4-4014-------------------------------------------------------------¿
|Roll010.06 P/4 measurements from basic MEASURE program |
| 1 3.42 2 13.01 3 4.11 4 2.77 5 2.69 6 3.56 7 2.08 8 0.14 |
| Area Periphery Length A-width M-width P-width M-valley P-valley|
| 9 1.72 10 1.74 11 1.02 12 0.70 13 0.62 14 2.28 15 1.35 16 1.98 |
|ALin-val. Lab-val. PLin-val. ALV-leng. ALV-width AC-height AV-height PC-heigh|
|17 1.33 18 0.00 19 42 20 77 21 79 22 4 23 0 24 2 25 2 26 0 |
|PV-height Lin-cusp ALV-wall ALV-P ALV-A Wear Lab-C AM-C PM-C Lin-C |
| |
| P/4 measurements calculated from above data |
|27 3.56 28 3.80 29 0.67 30 0.87 31 0.87 32 0.78 33 0.42 34 0.42|
|Max-width Per/area AW/len. PW/len. MaxW/len. AW/PW LiV/len. LaV/len|
| 35 0.51 36 0.03 37 48 38 1.69 39 1.49 |
| MV/len. PV/len. ALV*angle AC/val. PC/val. |
À------------------------------------------------------------------------------Ù
A = Orella A A
C = Orella C A CC
P = Pipestone AA CC
CC CC
A CC CC
C A CCA CC C
C C CCA CC C
C C CCC CCA C CC
C C CCC CCA C CCCC
C CACCC CCC CC CCCC
A C CACCCACCC CCCCCCCCC
A A C CCCCCCCCCCCCCCCCCCC
A A CAC ACCCCCCCCCCCCCCCCCCC
AAA A CCC CCCCCCCCCCCCCCCCCCCC AC
A A AAAA A A CCC CCCCCCCCCCCCCCCCCCCCC CACCC
AA AA AAAA AA AAA AA A CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC A C
AA AAAA AAAAAAA AAA AA A CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC A CC
A AAAA AAAAAAAAAAAAAACCA CC C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC CCCCC C C
A A A A A CACAAAAAAAAAAACCCCACCCACCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C C
+....+....+....+....+....+....+...^+....+....+....+....+....+.^..+....+....+....+....+....+....+
-4 -3 -2 -1 0 1 2 3
C
C
C C C
C C C
C C CC C C
C CCCC C C
C CCCC C C
C CCCC C C
P CC C CCCCC C C
C CC CPCCCCC C C
C CC CCCCCCCCC C
P C CCCCCCCCCCCC CC
P PCCCCCCCCCCCCCC CC P
P PC CCCCCCCCCCCCCCC CCC C
P P P P CC CPCCCCCCCCCCCCCCCCCCCCCC C
P P P P CC CCCCCCCCCCCCCCCCCCCCCCCC C
P P P P P CC CCCCCCCCCCCCCCCCCCCCCCCC C
P P PP PPP P CCCCCCCCCCCCCCCCCCCCCCCCCCC CC
P PPP P PP PPP P P P P P PCCCCCCCCCCCCCCCCCCCCCCCCCCC CCCCCCC
PPPPPPPPPPPPPPPPP PPPP P PPP CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
P PPP PPPPPPPPPPPPPPPPPPPPCPPPC CPC CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C C
+....+....+....+....+...^+....+....+....+....+....+....+....+...^+....+....+....+....+....+....+
-5 -4 -3 -2 -1 0 1 2 3 4
A
P A
P A
P AP
P A AA
P A A AAP A
P P P P P P PAA AA AAAA A
P PPPP P P P PP P AAAPAA AAAA A A
PPPPPP PPPPPP PPPP PPPA AAAAPAA AAAAAAAAAA
P P P PPPPPPPPPPPPPPPPPPP PP AAPA AAAAAAAAAAAAAAAAAAA AAA A
P P P PPP PPPPPPPPPPPPPPPPPPPAPP PAA AAAAAAAAAAAAAAAAAAAAAAAAA AAA AAA A
+....+....+....+....+....+....+....+^...+....+....+....+....+..^.+....+....+....+....+....+....+
-6 -4 -3 -2 -1 0 1 2 3 4
Scaled Dendrogram using Ward Method Locality
on Jaw, M/2, and M/3 measurements ÚBig Badlands (512) <I. typus, parvidens, troxelli
(overall size included) ÚÁOrella C (615)
ÚÅ-large Orella A (20)
Ú--------´À-Scotts Bluff (13)
| ÀÂ-Little Badlands (68) Large
Ú-----------------´ À-Slim Buttes (102) Orellan
| | Úsmall Colorado (31) Species
| | Ú-ÂÁLusk (148)
Large Size | À-------´ À-Late Chadron Complex (31)
Ú-------------------´ À---Lyman (18)
| | Ú---Â-----large Flagstaff (10)
| | Ú-------´ À-----large Pipestone (9) Mixed
| | Ú-------´ À---------McCarty's MTN (11) <T. douglassi Group
| À---´ À-----------------West Canyon Creek (10)
| À-------------------------large Colorado (3) <I. pliacus
| Ú-Â-small Flagstaff (52) Small
| Ú-´ À-Cameron Spring (14) Chadronian
| Ú---------´ À---small Pipestone (125) <T. veterior Group
| Ú-------´ À-----Beaver Divide (4) <T. wyomingensis
| | À---------------Harshman Quarry (1)
| Small Size | Ú--Âsmall Orella A (176) Small
À-------------------------´ Ú---´ ÀDouglas (70) Orellan Sp.
| Ú-----´ À---early Flagstaff (14)
| Ú-----´ Ã-------Ash Spring (2) Small
À---´ | À-------Cypress Hills (7) <I. junctus Chadronian
| À-------------Ledge Creek (2) Group
À-------------------Porvenir (1) <I. blacki
-3 -2 -1 0 1 2
2 2
West
*Canyon
Creek
*Harshman
Quarry
1 1
large
D *Pipestone
I
M large Cameron Beaver
*Orella A *small Spring* *Divide
Big Pipestone
large Badlands
*Colorado Orella *large Lusk *early *little
0 C **Flagstaff **Chadron Flagstaff Flagstaff 0
Slim* Scotts**Little *Lyman * Small* *Douglas
Buttes Bluff Badlands small Orella A
Colorado Ash *Cypress
*Spring Hills
T
W
O
-1 *Ledge -1
Creek
*McCarty's
Mountain
*Porvenir
-2 -2
-3 -2 -1 DIM 0 ONE 1 2
-2 -1 0 1 2 3
2 *Ash 2
Spring
West
*Canyon
Creek
Porvenir*
1 1
Douglas small
* Lusk**Orella A
D large Flagstaff*
I
M *small Colorado
early
Cameron* Flagstaff* Slim Orella
Spring Buttes *C
Little Badlands** *Big Badlands
0 Lyman** *Scotts 0
small* * Chadron Bluff
small Flagstaff large
Ledge* *Pipestone Orella A
Creek
T *Cypress
W Hills
O *McCarty's
Mountain
large
*Pipestone
-1 -1
Harshman
*Quarry
Beaver large
-2 *Divide *Colorado -2
-2 -1 DIM 0 ONE 1 2 3
Scaled Dendrogram using Ward Method Locality
on Jaw, M/2, and M/3 measurements ÚBig Badlands (512) <I. typus, parvidens, troxelli
(overall size excluded) Ú-ÂÁOrella C (615)
| ÃÂLittle Badlands (68)
Ú-´ |ÀSlim Buttes (102) Large
| | À-large Orella A (20) Orellan
Ú-´ Ã-Â-small Colorado (31) Species
| | | À-Late Chadron Complex (31)
Ú-------------------------´ | À---Lyman (18)
Ischyromys| | À-----Scotts Bluff (13)
Ú---------´ | Úsmall Orella A (176) Small
| | À-----ÂÁLusk (148) Orellan
| | À-Douglas (70) Species
| À---------------------------------Porvenir (1) <I. blacki
Ú-----´ Ú-Â-----early Flagstaff (14)
| | Ú-´ À-----large Flagstaff (10) Large
| | Ú-------´ À-------McCarty's MTN (11) <T. douglassi Chadronian
| | Ú---´ À---------large Pipestone (9) Group
| À---------------------´ À-----------------West Canyon Creek (10)
| Ancestral & Misc FormsÀ---------------------large Colorado (3) <I. pliacus
| Ú-Â-small Flagstaff (52)
| Ú---------´ À-Cameron Spring (14)
| Ú-------------´ À---small Pipestone (125) <T. veterior
| Ú---------´ À-------------Beaver Divide (4) <T. wyomingensis
| Titano- | | Ú---------Â---------------Ledge Creek (2) Small
À-----------´ À-´ À---------------Cypress Hills (7) <I. junctus Chadronian
theriomys | À-------------------------Harshman Quarry (1) Group
À-------------------------------------Ash Spring (2)
46¿JAW CONVEX JAW FLAT
| AND STEEP
| small *Lusk
| Orella A
45´ *
|
| Orella C* *small
| Colorado
44´ Douglas*
| Big
| Slim Buttes* *Badlands
| * *
43´ large Little *
| Orella A Badlands Harshman
| Quarry
| *Scotts
42´ Bluff
|
| Chadron* *Lyman
| Early *
41´ Ledge Beaver *West Canyon Ck. Flagstaff
| Creek Divide*
| * *small Flagstaff
| Cameron*
40´ *Ash Spr. Spring *large
| Colorado
| *
| McCarty's
39´ MTN
|
|
| * *
38´ small large
| Pipestone Flagstaff
|
|
37´
|
|
|
36´
| *large
|JAW FLAT Pipestone
|AND SHALLOW JAW CONCAVE
35Á---Â------Â------Â------Â------Â------Â------Â------Â----
^ 37 38 39 40 41 42 43 44
Posterior Anterior Jaw Angle
Jaw Angle
| M/2 large Colorado*
| SHORTER
| large Pipestone*
|
| Slim*
3.9´ Scotts Buttes
| Bluff Little
| * *Badlands
| McCarty's MTN* *large
| Orella C* Orella A
| *Big Badlands
|
| *Lyman
|
|
| Chadron small
3.6´ * *Colorado
| Porvenir
| * * *large
| Lusk Flagstaff
|
| Harshman
| small* * *West Canyon Creek
| Orella A
| *Ledge Creek
| *
| Douglas
3.3´
| early* *small
| Flagstaff Pipestone
|
|
| *Beaver Divide
|
| *Ash Spring
| *small
| * Flagstaff
|Cameron
3.0´
|
|
|
| M/3
| *Cypress Hills SHORTER
Ã-----------------Â-----------------Â-----------------Â--
^ 3.0 3.3 3.6 3.9
M/3 M/2 Length
Length
0.8¿ POSTERIOR *McCarty's
| END LARGE MTN
|
| Scotts large
| West Bluff Pipestone
| Canyon * *
| *Creek
| Ledge Lyman* *large
| Creek**Harshman * Orella A
| Quarry Orella C
| large *
0.7´ Colorado
| *Big
| Lusk* small Badlands
| Colorado
| * *Little
| small *large Badlands
| Orella A Flagstaff
| * *Chadron Slim*
| *early Buttes
| Flagstaff
|
0.6´
|
| *Douglas
|
|
| *Cypress
| Hills
|
|
|
| *Ash
0.5´ Spring
| small
| Flagstaff
| *
| *Beaver Divide
|
| *Cameron Spring
| *
| Porvenir
| *small POSTERIOR END
| Pipestone COMPRESSED
0.4Å-----------------Â-----------------Â-----------------Â--
^ 3.0 3.3 3.6 3.9
M/3 Post. M/2 Length
Length
| *large LARGE
| Colorado
7.5´
|
| large
| Pipestone
| *
| *Slim
| Buttes
|
| Scotts
| large* *Bluff
7.0´ Orella A *Little
| Badlands
| Big McCarty's*
| Orella C* *Badlands MTN
|
| Lyman*
| *large
| Flagstaff
| small
| *Colorado
6.5´ Chadron*
|
| *Lusk *West Canyon Creek
|
|
|
|*Harshman
| Quarry Orella A Porvenir
| * *
| Douglas* *small *Ledge
6.0´ Pipestone Creek
| *Beaver
| Divide
| *early
|*Ash Flagstaff
| Spring
| small
| *Flagstaff
| *
| Cameron
5.5´ Spring *Cypress
| Hills SMALL
À-Â------------Â------------Â------------Â------------Â--
^ 70 90 110 130 150
Area of Posterior Angle - Wall Angle of
M/2+M/3 Anterior Lingual Valley of M/2+M/3
| large*
| Colorado
7.5´
|
|
| Slim
| Buttes*
| large *
| Pipestone
|
| large Scotts
| Orella A* *Bluff
7.0´ *
| Little Badlands
| *McCarty's MTN
| Big* *Orella
| Badlands C
| large *
| *Flagstaff Lyman
|
|
| small*
6.5´ Colorado *Chadron
|
| West* *
| Canyon Lusk
| Creek
|
|*Harshman
| Quarry small
| Ledge Douglas *Orella A
| Creek* * *
6.0´ small
| *Beaver Pipestone
| Divide
|* Ash
|early Spring*
|Flagstaff
| small
| Flagstaff*
| *Cameron
| Spring
5.5´LOW Cypress* HIGH
|CUSPS Hills CUSPS
Ã---------Â---------Â---------Â---------Â---------Â------
^ 5.6 5.8 6.0 6.2 6.4 6.8
Area of Ant. Cusp Height/Ant. Valley Height +
M/2+M/3 Post. Cusp Height/Post. Valley Height of M/2+M/3
Age (MY) Texas Wyoming-Nebraska Montana Saskatchewan
------------------------------------------------------------------------
Whitneyan
30 ---------------------- Orella C -------------------------------------
ÉÍÍ (I. typus) Orellan
º
º Orella A Orellan
31 ----------------- º (I. parvidens) ----------------------------------
º º Chadronian
ÈÍÍ Late Chadron
Complex
32 (I. sp.)
º
ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ
º small Pipestone
33 º Ash Spring large Flagstaff ÉÍ (T. veterior)
º (T. n.s.) (T. n.s.) º large Pipestone
º º ÉÍÍÍÍÍÍÍͼ º (T. n.s.)
º º º small Flagstaff,º º
34 º º º Cameron Spring, º º
º º º Beaver Divide º ÉÍÍÍÍÍͼ
º º º (T. veterior) º º
º º º ÌÍÍÍÍÍÍÍͼ º McCarty's
35 º º º º Éͼ Mountain Cypress
º º º º º (T. douglassi) Hills
º º º º º º (T. junctus)
º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÎÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ
36 º ÈÍearly Flagstaffͼ º
Ì?ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ (T. veterior) ÍÍÍÍÍÍÍÍÍͼ
Ì?ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» º
Ì?ÍÍÍÍÍÍÍÍÍÍÍÍÍ» º ?ÍÍÍÍÍÍÍÍÍÍÍÍÍ»
37 Ì?ÍÍÍÍÍÍÍ» º ÈÍÍÍÍͺÍÍÍÍÍÍÍÍÍÍÍÍ͹
? º ÈÍÍÍÍÍÍÍÍÍÍ͹ º Chadronian
---º--- Porvenir ---- West Canyon Creek ----º---------------------------
º (I. blacki) ÍÍ??ÍÍ (I. n.s.) º Duchesnean
38 ÈÍÍÍÍÍÍÍÍËÍÍÍÍÍÍÍͼÈÍÍÍÍÍÍÍËÍÍÍÍÍÍÍÍÍÍÍÍͼ
º Badwater Creek
? (taxon indet.)
Timothy H. Heaton:
E-mail,
Home page,
Phone (605) 677-6122, FAX (605) 677-6121