| 1. | Premaxilla, anterior margin of premaxilla sloped posterodorsally in lateral view |
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| (Nanotyrannus) versus vertically oriented (Tyrannosaurus) †; |
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| 2. | Premaxilla, ventral margin distinctly upturned in lateral view (Nanotyrannus) or horizontal |
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| (Tyrannosaurus) † (autapomorphy). |
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| 3. | Premaxilla, articulated premaxillae form a long, narrow U in dorsal or ventral view |
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| (Nanotyrannus) or very short, and broad transversely (Tyrannosaurus); |
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| 4. | Premaxilla, subnarial process faces anterolaterally (Nanotyrannus) or anteriorly |
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| (Tyrannosaurus) †; |
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| Maxilla |
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| 5. | Maxilla, sculpture of maxilla weakly developed, simple rugosity (Nanotyrannus) or forming |
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| ridges and deep depressions on lateral surface of maxilla (Tyrannosaurus) *; |
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| 6. | Maxilla, subnarial fossa and foramen exposed in lateral view (Nanotryannus) or obscured in |
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| lateral view (Tyrannosaurus) †; |
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| 7. | Maxilla, maxillae narrow in dorsal view (Nanotyrannus) versus muzzle broad in dorsal view |
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| (Tyrannosaurus); |
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| 8. | Maxilla, maxilla long and low, more than twice as long as tall (Nanotyrannus), versus short |
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| and tall (Tyrannosaurus) †; |
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| 9. | Maxilla, ventral margin of maxilla weakly convex or straight (Nanotyrannus), or strongly |
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| curved, projecting strongly downwards relative to jugal process (Tyrannosaurus) *; |
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| 10. | Maxilla, nasal closely approaches anterodorsal margin of antorbital fossa (Nanotyrannus) or |
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| maxilla broadly separates nasal from antorbital fossa (Tyrannosaurus) *; |
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| 11. | Maxilla, antorbital fossa shallow (Nanotyrannus) or deep (Tyrannosaurus) †; |
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| 12. | Maxilla, promaxillary fenestra visible in lateral view (Nanotyrannus) or concealed in lateral |
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| view (Tyrannosaurus) †; |
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| 13. | Maxilla, accessory antorbital fenestra small and does not reach anterior end of antorbital |
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| fossa (Nanotyrannus) versus large and reaches anterior end of antorbital fossa |
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| (Tyrannosaurus) †; |
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| 14. | Maxilla, accessory antorbital fenestra lies well above ventral margin of antorbital fossa |
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| (Nanotyrannus) versus ventrally positioned (Tyrannosaurus) †; |
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| 15. | Maxilla, antorbital fossa with a broad rim beneath the antorbital fenestra (Nanotyrannus) |
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| versus antorbital fossa with a very narrow exposure along the posteroventral margin of the |
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| antorbital fenestra (Tyrannosaurus) †; |
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| 16. | Maxilla, broad posterodorsal process of maxilla extends posterodorsally and defines a wide |
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| antorbital fossa above antorbital fenestra and under the nasals (Nanotyrannus) versus very |
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| narrow contribution to antorbital fossa below nasals (Tyrannosaurus) †; |
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| 17. | Maxilla, antorbital fenestra with a narrow U- or V-shaped anterior margin (Nanotyrannus) |
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| versus a broadly U-shaped or squared-off anterior margin (Tyrannosaurus) †; |
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| 18. | Maxilla, promaxillary recess small (Nanotyrannus) or greatly enlarged (Tyrannosaurus); |
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| 19. | Maxilla, deep recess on medial surface of maxilla above maxillary fenestra absent |
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| (Nanotyrannus) or present (Tyrannosaurus); |
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| 20. | Maxilla, sinus on medial surface of maxilla posterodorsal to maxillary fenestra, small and |
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| shallow (Nanotyrannus) or deep and extensive (Tyrannosaurus); |
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| 21. | Maxilla, internal antorbital fossa weakly developed (Nanotyrannus) or extensive |
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| (Tyrannosaurus); |
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| 22. | Maxilla, articulation for vomer and palatal shelves lies ventrally (Nanotyrannus) or elevated |
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| well above interdental plates (Tyrannosaurus); |
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| 23. | Maxilla, occlusal pits weakly developed or absent (Nanotyrannus) or well-developed and |
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| prominent on inside of maxilla (Tyrannosaurus); |
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| 24. | Maxilla extends caudally under orbit (Nanotyrannus) or only as far as beneath the lacrimal |
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| bar (Tyrannosaurus) *; |
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| 25. | Maxilla, maxilla-palatine contact straight (Nanotyrannus) strongly curved (Tyrannosaurus). |
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| Nasals |
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| 26. | Nasals, nasal premaxillary processes wide in dorsal view (Nanotyrannus) or narrow where |
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| they approach and clasp premaxillae (Tyrannosaurus) †; |
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| 27. | Nasals, nasals narrow (Nanotyrannus) versus transversely broad (Tyrannosaurus) †; |
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| 28. | Nasals, nasals relatively flat and low in lateral view (Nanotyrannus) versus strongly arched |
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| transversely and tall in lateral view (Tyrannosaurus) *, |
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| 29. | Nasals, nasals broad posteriorly where they contact the frontals (Nanotyrannus) versus |
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| narrow and strongly tapered posteriorly where they contact the frontals (Tyrannosaurus) *; |
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| 30. | Nasals, nasals form a relatively smooth contact with maxillae (Nanotyrannus) versus a |
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| strongly interdigitating contact with notches fitting into the maxillae (Tyrannosaurus) *; |
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| 31. | Nasals, nasals flat posteriorly (Nanotyrannus) or with a dorsal depression or groove, and |
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| lateral edges of nasals upturned to contribute to nasolacrimal ridge (Tyrannosaurus) †. |
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| Lacrimal |
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| 32. | Lacrimal, lacrimal L-shaped in lateral view, anterior and ventral rami diverging at |
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| approximately a right angle (Nanotyrannus) or anterior and ventral rami diverging at an |
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| acute angle in lateral view (Tyrannosaurus) *; |
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| 33. | Lacrimal, anterior process similar to ventral process in length (Nanotyrannus) or anterior |
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| process much shorter than ventral process (Tyrannosaurus) †; |
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| 34. | Lacrimal, lacrimal with a low, crescent-shaped lacrimal horn (Nanotyrannus) or lacrimal |
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| horn reduced to a low, broad rugosity (Tyrannosaurus) †; |
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| 35. | Lacrimal, lacrimal horn mediolaterally narrow and with a narrow apex (Nanotyrannus) or |
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| strongly inflated and a transversely broad, rounded apex (Tyrannosaurus) *; |
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| 36. | Lacrimal, lacrimal horn with a broad, strongly emarginated pneumatic excavation with |
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| multiple large foramina (Nanotyrannus) versus reduced pneumatic excavation with a small |
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| foramen (Tyrannosaurus) *; |
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| 37. | Lacrimal, broad development of antorbital fossa on base of lacrimal ventral ramus |
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| (Nanotyrannus) versus anteroposteriorly narrow exposure of antorbital fossa (Tyrannosaurus); |
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| 38. | Lacrimal, orbital bar strongly curved (Nanotyrannus) versus relatively straight |
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| (Tyrannosaurus) †; |
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| 39. | Lacrimal, bone T-shaped in lateral view, with a large posterior process (Nanotyrannus) or |
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| L-shaped, with a short posterior process (Tyrannosaurus) *; |
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| 40. | Lacrimal, lacrimal with low medial flange (Nanotyrannus) or prominent medial flange (Tyrannosaurus); |
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| 41. | Lacrimal, medial surface with a small foramen in antorbital fossa (Nanotyrannus) or enlarged pneumatic opening in the antorbital fossa (Tyrannosaurus); |
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| 42. | Lacrimal, large, shallow depression on medial surface of lacrimal (Nanotyrannus) or small deep fossa (Tyrannosaurus). |
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| Frontals 43. Frontals, frontals participate in orbital margin (Nanotyrannus) or excluded from orbit by postorbital-lacrimal contact (Tyrannosaurus) †; |
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| 44. | Frontals, frontal table long and narrow in dorsal view (Nanotyrannus) versus short and wide (Tyrannosaurus) †; |
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| 45. | Frontal, short contribution of frontal to sagittal crest, with parietal forming most of the crest (Nanotyrannus) or long frontal contribution to sagittal crest (Tyrannosaurus) †; |
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| 46. 47. | Frontals, supratemporal fossae short (Nanotyrannus) versus very long (Tyrannosaurus) *; Frontals, frontals broad anteriorly between lacrimals (Nanotyrannus) versus strongly constricted between lacrimals (Tyrannosaurus) †; |
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| 48. | Frontals, supratemporal fossa with a concave anterior margin (Nanotyrannus) or S-shaped margin of supratemporal fossae, being strongly extended forward medially (Tyrannosaurus); |
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| 49. | Frontals, distinct downflex of supratemporal fossae relative to frontal table absent (Nanotyrannus) or present, and supratemporal fossae distinctly sloped downward relative to (Tyrannosaurus) †; |
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| 50. | Frontals, frontal-postorbital suture shallow in lateral view (Nanotyrannus) or dorsoventrally extensive (Tyrannosaurus) †. |
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| Parietal 51. Parietal, nuchal crest in posterior view with pointed dorsolateral corners (Nanotyrannus) or broadly rounded (Tyrannosaurus); |
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| 52. | Parietal, posterior surface of nuchal crest with broad ridge (Nanotyrannus) or a sharp, narrow, well-defined ridge (Tyrannosaurus); |
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| 53. | Parietal, parietal nuchal crest straight in dorsal view (Nanotyrannus) or arcuate, projecting back along midline and wrapping forward laterally (Tyrannosaurus). |
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| Postorbital 54. Postorbital, postorbital with a rudimentary postorbital boss (Nanotyrannus), versus a massive, dorsoventrally extended postorbital boss (Tyrannosaurus) *; |
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| 55. | Postorbital, jugal process anteroposteriorly narrow (Nanotyrannus) versus anteroposteriorly broad (Tyrannosaurus) *; |
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| 56. | Postorbital, suborbital flange rudimentary (Nanotyrannus) versus expanded and constricting orbit (Tyrannosaurus) *; |
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| 57. | Postorbital, straight contact with the jugal (Nanotyrannus) versus jugal contact strongly convex (Tyrannosaurus) *; |
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| 58. | Postorbital, squamosal process narrow and splintlike (Nanotyrannus) or a dorsoventrally deep, triangular structure (Tyrannosaurus) *; |
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| 59. | Postorbital, main body of postorbital shallow (Nanotyrannus) or dorsally extended above squamosal process (Tyrannosaurus) *; |
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| 60. | Postorbital, anterior end of postorbital shallow (Nanotyrannus) or deep and massive where it contacts frontals and lacrimals (Tyrannosaurus) *; |
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| 61. | Postorbital, anterior end of postorbital projects anteriorly (Nanotyrannus) hooked downward anteriorly (Tyrannosaurus); |
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| 62. | Postorbital, fossa on medial surface of postorbital present (Nanotyrannus) or absent (Tyrannosaurus). |
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| Jugal 63. Jugal, antorbital fossa extends beneath lacrimal (Nanotyrannus) or lies largely anterior to ventral process of lacrimal (Tyrannosaurus) *; |
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| 64. | Jugal, body of jugal narrow anteriorly beneath lacrimal (Nanotyrannus) versus dorsoventrally expanded relative to depth beneath orbit (Tyrannosaurus) †; |
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| 65. | Jugal, jugal with a wide, shallowly concave orbital margin (Nanotyrannus) versus jugal contribution to orbit a deep, narrow notch (Tyrannosaurus) *; |
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| 66. | Jugal, jugal with a small pneumatic opening at the corner of the antorbital fossa (Nanotyrannus) versus a large dorsally positioned one (Tyrannosaurus) *; |
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| 67. | Jugal, pneumatic recess shallow (Nanotyrannus) or deeply excavating the jugal (Tyrannosaurus) *; |
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| 68. | Jugal, notch for postorbital small (Nanotyrannus) or enlarged to receive a broad ventral process of the jugal (Tyrannosaurus) *; |
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| 69. | Jugal, postorbital process anteroposteriorly narrow where it contacts postorbital (Nanotyrannus) or anteroposteriorly broad (Tyrannosaurus); |
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| 70. | Jugal, narrow articulation for the postorbital (Nanotyrannus) or contacts postorbital via a broadly overlapping lap joint (Tyrannosaurus); |
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| 71. 72. | Jugal, quadratojugal ramus short (Nanotyrannus) versus elongate (Tyrannosaurus) †; Jugal, posterior ramus extends horizontally (Nanotyrannus) or dorsal margin deflected upwards (Tyrannosaurus) †. |
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| Quadratojugal |
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| 73. | Quadratojugal, forms an anteroposteriorly short contact with squamosal (Nanotyrannus) versus a broad squamosal contact (Tyrannosaurus); |
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| 74. | Quadratojugal, anterior process of quadratojugal narrow (Nanotyrannus) versus deep (Tyrannosaurus); |
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| 75. 76. | Quadratojugal, dorsal margin concave (Nanotyrannus) straight or convex (Tyrannosaurus); Quadratojugal, quadratojugal anterior ridge narrow and tapers distally (Nanotyrannus) or massive and extends to end of quadratojugal (Tyrannosaurus); |
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| 77. | Quadratojugal, pneumatic foramen pierces lateral surface of quadratojugal (Nanotyrannus) or pneumatic foramen absent (Tyrannosaurus) (autapomorphy); |
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| 78. | Quadratojugal, posterior process extends posteriorly (Nanotyrannus) or posterodorsally to wrap onto posterior face of quadrate (Tyrannosaurus); |
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| 79. | Quadrate, quadratojugal pneumatic foramen present (Nanotyrannus) or absent (Tyrannosaurus) †. |
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| Squamosals |
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| 80. | Squamosals, caudal ends of squamosals do not extend far past parietal in dorsal view (Nanotyrannus) versus squamosals project strongly posterior to parietals in dorsal view (Tyrannosaurus); |
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| 81. | Squamosal, ventral fossa of squamosal bounded anteriorly by a narrow bar of bone (Nanotyrannus) or a broad, shallow shelf (Tyrannosaurus); |
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| 82. | Squamosal, anterior lamina does not extend forward (Nanotyrannus) or extends forward to anterior end of squamosal (Tyrannosaurus); |
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| 83. | Squamosal, ventral fossa lacks a pneumatic recess (Nanotyrannus) or pneumatic recess present in the roof of the ventral fossa (Tyrannosaurus); |
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| 84. | Squamosal, quadratojugal process forming a narrow point anteriorly (Nanotyrannus) or a broad rounded or subrectangular tip (Tyrannosaurs). |
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| Vomer |
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| 85. 86. 87. | Vomer, vomer narrow anteriorly (Nanotyrannus) or transversely expanded (Tyrannosaurus); Vomer, distal end dorsoventrally expanded (Nanotyrannus) or low (Tyrannosaurus); Vomer, proximal end dorsoventrally expanded (Tyrannosaurus). |
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| Palatine |
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| 88. | Palatine, dorsal process of palatine lacks posterior expansion (Nanotyrannus) or bears a large, broad posterior expansion (Tyrannosaurus); |
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| 89. | Palatine, neck of dorsal process projects anterodorsally (Nanotyrannus) or dorsally (Tyrannosaurus) *; |
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| 90. | Palatine, anterior prong of dorsal process long and slender (Nanotyrannus) or short and robust (Tyrannosaurus); |
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| 91. 92. 93. | Palatine, pneumatic fossae small (Nanotyrannus) or enlarged (Tyrannosaurus); Palatine, body weakly inflated (Nanotyrannus) or strongly inflated (Tyrannosaurus); Palatine, anteroventral process slender (Nanotyrannus) or proportionately short and broad (Tyrannosaurus). |
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| Ectopterygoid |
|---|
| 94. | Ectopterygoid, opening of pneumatic recess a thin slot (Nanotyrannus) or a large aperture (Tyrannosaurus); |
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| 95. | Ectopterygoid, posterior edge of pneumatic recess flat (Nanotyrannus) or bounded by a distinct lip (Tyrannosaurus); |
|---|
| 96. | Ectopterygoid, jugal process lacks a pneumatic foramen (Nanotyrannus) or with a large |
|---|
| pneumatic foramen (Tyrannosaurus); |
|---|
| 97. | Ectopterygoid, ectopterygoid weakly expanded (Nanotyrannus) strongly inflated |
|---|
| (Tyrannosaurus). |
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| Braincase |
|---|
| 98. | Supraoccipital, subrectangular (Nanotyrannus) forked dorsally (Tyrannosaurus); |
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| 99. | Exoccipitals, paroccipital processes taper in posterior view (Nanotyrannus) or distally broad |
|---|
| (Tyrannosaurus); |
|---|
| 100. | Exoccipitals, paroccipital processes extend laterally (Nanotyrannus) versus posterolaterally |
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| (Tyrannosaurus); |
|---|
| 101. | Parasphenoid, rostrum long, slender and triangular in lateral view (Nanotyrannus) or |
|---|
| proportionately short, deep and rectangular in shape (Tyrannosaurus) *; |
|---|
| 102. | Basioccipital with prominent depressions ventrolateral to the occipital condyle and |
|---|
| extending onto the basal tubera in posterior view (Nanotyrannus) or absent (Tyrannosaurus); |
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| 103. | Basioccipital, basal tubera separated by a deep, narrow notch (Nanotyrannus) versus a |
|---|
| shallow, wide notch (Tyrannosaurus); |
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| 104. | Basioccipital, basal tubera wider than basispterygoid processes and extremely wide relative |
|---|
| to skull width (Nanotyrannus) or as wide or narrower than basipterygoid processes |
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| (Tyrannosaurus) (autapomorphy); |
|---|
| 105. | Basisphenoid, basisphenoid recess, faces posteroventrally (Nanotyrannus) or strongly |
|---|
| directed posteriorly (Tyrannosaurus). |
|---|
| Dentary |
|---|
| 106. | Dentary, anteroventral margin of dentary symphysis rises up at a shallow angle |
|---|
| (Nanotyrannus) versus rises up steeply (Tyrannosaurus); |
|---|
| 107. | Dentary, anterior end of dentary shallow (Nanotyrannus) or distinctly expanded relative to |
|---|
| midlength (Tyrannosaurus); |
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| 108. | Dentary, symphysis weakly developed (Nanotyrannus) or massive facet where dentaries |
|---|
| contact (Tyrannosaurus); |
|---|
| 109. | Dentary, symphysis ends beneath fourth tooth (Nanotyrannus) or third (Tyrannosaurus); |
|---|
| 110. | Dentary, interdental plates weakly developed, tapering dorsally (Nanotyrannus) or large and |
|---|
| broad, covering much of the tooth roots (Tyrannosaurus) †; |
|---|
| 111. | Dentary, first two alveoli small (Nanotyrannus), or first alveolus small (Tyrannosaurus) †; |
|---|
| 112. | Dentary, lingual bar covers first alveolus (Nanotyrannus) or first two alveoli (Tyrannosaurus); |
|---|
| 113. | Dentary, dentary groove present and well-defined (Nanotyrannus) or reduced/absent |
|---|
| (Tyrannosaurus); |
|---|
| 114. | Dentary, neurovascular foramina in small pits (Nanotyrannus) or set in deep grooves |
|---|
| (Tyrannosaurus); |
|---|
| 115. | Dentary, ventral margin bowed (Nanotyrannus) or straight (Tyrannosaurus); |
|---|
| 116. | Dentary, neurovascular foramina lie low on dentary (Nanotyrannus) or high on dentary |
|---|
| (Tyrannosaurus); |
|---|
| 117. | Dentary, toothrow straight or weakly curved in dorsal view (Nanotyrannus) versus bowed |
|---|
| outwards anteriorly in dorsal view to create a broad, U-shaped jaw (Tyrannosaurus); |
|---|
| 118. | Dentary, weakly expanded posteriorly (Nanotyrannus) versus strongly expanded posteriorly |
|---|
| to about twice its minimum depth (Tyrannosaurus); |
|---|
| 119. | Dentary, lingual bar similar in depth anteriorly and posteriorly (Nanotyrannus) versus |
|---|
| narrow and tapered posteriorly relative to the anterior of the toothrow (Tyrannosaurus); |
|---|
| 120. | Dentary, facet for articulation with splenial below Meckelian fossa weakly developed |
|---|
| (Nanotyrannus) or large, very broad contact surface (Tyrannosaurus); |
|---|
| 121. | Dentary, Meckelian fossa narrow and V-shaped anteriorly (Nanotyrannus) or broad and |
|---|
| U-shaped (Tyrannosaurus); |
|---|
| 122. | Dentary, contact with surangular straight (Nanotyrannus) or strongly concave |
|---|
| (Tyrannosaurus); |
|---|
| 123. | Dentary, weak notch of angular process (Nanotyrannus) or very strong forking of angular |
|---|
| process (Tyrannosaurus). |
|---|
| Posterior Mandible |
|---|
| 124. | Splenial, mylohyoid foramen long and low (Nanotyrannus) or short and tall (Tyrannosaurus); |
|---|
| 125. | Angular, posteroventral margin strongly convex (Nanotyrannus) or relatively straight |
|---|
| (Tyrannosaurus); |
|---|
| 126. | Prearticular, weakly bowed (Nanotyrannus) or strongly bowed (Tyrannosaurus); |
|---|
| 127. | Prearticular, midshaft flattened, plate-like (Nanotyrannus) or rounded, width and height |
|---|
| subequal (Tyrannosaurus) |
|---|
| 128. | Surangular, groove and enlarged foramen absent (Nanotyrannus) or present (Tyrannosaurus); |
|---|
| 129. | Surangular, lateral shelf short (Nanotyrannus) or elongate, extending about half the length of |
|---|
| the surangular (Tyrannosaurus); |
|---|
| 130. | Surangular, shallow below surangular foramen (Nanotyrannus) versus very deep below |
|---|
| surangular foramen (Tyrannosaurus); |
|---|
| 131. | Surangular, long and low (Nanotyrannus) or short and deep (Tyrannosaurus) *; |
|---|
| 132. | Surangular, coronoid process weakly developed (Nanotyrannus) or tall and anteroposteriorly |
|---|
| expanded (Tyrannosaurus); |
|---|
| 133. | Surangular, surangular shelf thin (Nanotyrannus) or thick and massive (Tyrannosaurus); |
|---|
| 134. | Surangular, surangular foramen lies just anterior to condyle (Nanotyrannus) or well anterior |
|---|
| to condyle (Tyrannosaurus); |
|---|
| 135. | Articular, subrectangular medial projection in caudal view (Nanotyrannus) or articular |
|---|
| smoothly rounded and semicircular to crescentic in posterior view (Tyrannosaurus). |
|---|
| Dentition |
|---|
| 136. | Dentition, premaxillary teeth procumbent (Nanotyrannus) or project vertically down |
|---|
| (Tyrannosaurus) † (autapomorphy); |
|---|
| 137. | Dentition, premaxillary tooth apices blunt and chisel-like (Nanotyrannus) versus sharp and |
|---|
| pointed (Tyrannosaurus) †; |
|---|
| 138. | Dentition, premaxillary teeth unserrated in adults (Nanotyrannus) versus serrated |
|---|
| (Tyrannosaurus) † (autapomorphy); |
|---|
| 139. | Dentition, premaxillary teeth subequal in size (Nanotyrannus) or first tooth small relative to |
|---|
| successive teeth (Tyrannosaurus) †; |
|---|
| 140. | Dentition, number of dentary teeth: 13 (0), 14 (1), 15 (2), 16 (3), 17 (4) †; |
|---|
| 141. | Dentition, number of maxillary teeth: 11 (0), 12 (1), 13 (2), 14 (3), 15 (4) †; |
|---|
| 142. | Dentition, maxilla with a small, incisiform first tooth (Nanotyrannus) or maxilla with large |
|---|
| and pointed first tooth (Tyrannosaurus) †; |
|---|
| 143. | Dentition, maxillary and dentary teeth laterally compressed and with rectangular bases |
|---|
| (Nanotyrannus) versus broad and ovate (Tyrannosaurus) *; |
|---|
| 144. | Dentition, anterior teeth of maxilla and dentary not markedly enlarged relative to more |
|---|
| posterior teeth (Nanotyrannus) or caniniform teeth in anterior maxilla and dentary |
|---|
| (Tyrannosaurus) †; |
|---|
| Postcrania |
|---|
| 145. | Scapula, broad shaft relative to coracoid articulation (Nanotyrannus) or narrow neck and |
|---|
| very broad coracoid expansion, about three times width of shaft just above the acromion |
|---|
| (Tyrannosaurus); |
|---|
| 146. | Coracoid, short and wide (Nanotyrannus) or tall, height about equal to width across scapular |
|---|
| facet (Tyrannosaurus); |
|---|
| 147. | Humerus, proximal head small and ellipsoidal (Nanotyrannus) or massive, bulbous, and |
|---|
| proximally projecting (Tyrannosaurus); |
|---|
| 148. | Humerus, internal tuberosity small, well-differentiated, and distally placed (Nanotyrannus) |
|---|
| or large, poorly differentiated, and proximally placed (Tyrannosaurus); |
|---|
| 149. | Manus, manual unguals large (Nanotyrannus) or highly reduced (Tyrannosaurus); |
|---|
| 150. | Ilium, blade long and low (Nanotyrannus) or tall (Tyrannosaurus); |
|---|
| 151. | Ilium, blade with a straight dorsal margin (Nanotyrannus) versus convex (Tyrannosaurus); |
|---|
| 152. | Pubis, pubic boot slender (Nanotyrannus) deep in lateral view (Tyrannosaurus); |
|---|
| 153. | Femur, femur with large accessory trochanter (Nanotyrannus) or a small accessory trochanter |
|---|
| (Tyrannosaurus); |
|---|
| 154. | Femur, femoral head elevated (Nanotyrannus) versus weakly elevated (Tyrannosaurus); |
|---|
| 155. | Femur, fourth trochanter small (Nanotyrannus) versus massive (Tyrannosaurus); |
|---|
| 156. | Tibia, cnemial crest long and narrow, tapering and triangular in profile (Nanotyrannus) or |
|---|
| proportionately short and broad, with a squared-off end (Tyrannosaurus); |
|---|
| 157. | Metatarsus, shaft of metatarsal III straight (Nanotyrannus) or twisted in anterior view |
|---|
| (Tyrannosaurus); |
|---|
| 158. | Metatarsal III, ventral surface of MT III with a narrow keel (Nanotyrannus) or a broad ventral |
|---|
| tubercle or ‘pillar’ (Tyrannosaurus); |
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| Body Size |
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| 159. | Small size (estimated skull length ≤ 90 cm) or large (>90 skull length); |
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