DOI: 10.5281/zenodo.15157869
title: Table 4 in Taxonomic Status of Nanotyrannus lancensis (Dinosauria: Tyrannosauroidea) - A Distinct Taxon of Small-Bodied Tyrannosaur

description: Table 4. Morphological characters differentiating Nanotyrannus and Tyrannosaurus.
Premaxilla1.Premaxilla, anterior margin of premaxilla sloped posterodorsally in lateral view(Nanotyrannus) versus vertically oriented (Tyrannosaurus) †;2.Premaxilla, ventral margin distinctly upturned in lateral view (Nanotyrannus) or horizontal(Tyrannosaurus) † (autapomorphy).3.Premaxilla, articulated premaxillae form a long, narrow U in dorsal or ventral view(Nanotyrannus) or very short, and broad transversely (Tyrannosaurus);4.Premaxilla, subnarial process faces anterolaterally (Nanotyrannus) or anteriorly(Tyrannosaurus) †;Maxilla5.Maxilla, sculpture of maxilla weakly developed, simple rugosity (Nanotyrannus) or formingridges and deep depressions on lateral surface of maxilla (Tyrannosaurus) *;6.Maxilla, subnarial fossa and foramen exposed in lateral view (Nanotryannus) or obscured inlateral view (Tyrannosaurus) †;7.Maxilla, maxillae narrow in dorsal view (Nanotyrannus) versus muzzle broad in dorsal view(Tyrannosaurus);8.Maxilla, maxilla long and low, more than twice as long as tall (Nanotyrannus), versus shortand tall (Tyrannosaurus) †;9.Maxilla, ventral margin of maxilla weakly convex or straight (Nanotyrannus), or stronglycurved, projecting strongly downwards relative to jugal process (Tyrannosaurus) *;10.Maxilla, nasal closely approaches anterodorsal margin of antorbital fossa (Nanotyrannus) ormaxilla broadly separates nasal from antorbital fossa (Tyrannosaurus) *;11.Maxilla, antorbital fossa shallow (Nanotyrannus) or deep (Tyrannosaurus) †;12.Maxilla, promaxillary fenestra visible in lateral view (Nanotyrannus) or concealed in lateralview (Tyrannosaurus) †;13.Maxilla, accessory antorbital fenestra small and does not reach anterior end of antorbitalfossa (Nanotyrannus) versus large and reaches anterior end of antorbital fossa(Tyrannosaurus) †;14.Maxilla, accessory antorbital fenestra lies well above ventral margin of antorbital fossa(Nanotyrannus) versus ventrally positioned (Tyrannosaurus) †;15.Maxilla, antorbital fossa with a broad rim beneath the antorbital fenestra (Nanotyrannus)versus antorbital fossa with a very narrow exposure along the posteroventral margin of theantorbital fenestra (Tyrannosaurus) †;16.Maxilla, broad posterodorsal process of maxilla extends posterodorsally and defines a wideantorbital fossa above antorbital fenestra and under the nasals (Nanotyrannus) versus verynarrow contribution to antorbital fossa below nasals (Tyrannosaurus) †;17.Maxilla, antorbital fenestra with a narrow U- or V-shaped anterior margin (Nanotyrannus)versus a broadly U-shaped or squared-off anterior margin (Tyrannosaurus) †;18.Maxilla, promaxillary recess small (Nanotyrannus) or greatly enlarged (Tyrannosaurus);19.Maxilla, deep recess on medial surface of maxilla above maxillary fenestra absent(Nanotyrannus) or present (Tyrannosaurus);20.Maxilla, sinus on medial surface of maxilla posterodorsal to maxillary fenestra, small andshallow (Nanotyrannus) or deep and extensive (Tyrannosaurus);21.Maxilla, internal antorbital fossa weakly developed (Nanotyrannus) or extensive(Tyrannosaurus);22.Maxilla, articulation for vomer and palatal shelves lies ventrally (Nanotyrannus) or elevatedwell above interdental plates (Tyrannosaurus);23.Maxilla, occlusal pits weakly developed or absent (Nanotyrannus) or well-developed andprominent on inside of maxilla (Tyrannosaurus);24.Maxilla extends caudally under orbit (Nanotyrannus) or only as far as beneath the lacrimalbar (Tyrannosaurus) *;25.Maxilla, maxilla-palatine contact straight (Nanotyrannus) strongly curved (Tyrannosaurus).Nasals26.Nasals, nasal premaxillary processes wide in dorsal view (Nanotyrannus) or narrow wherethey approach and clasp premaxillae (Tyrannosaurus) †;27.Nasals, nasals narrow (Nanotyrannus) versus transversely broad (Tyrannosaurus) †;28.Nasals, nasals relatively flat and low in lateral view (Nanotyrannus) versus strongly archedtransversely and tall in lateral view (Tyrannosaurus) *,29.Nasals, nasals broad posteriorly where they contact the frontals (Nanotyrannus) versusnarrow and strongly tapered posteriorly where they contact the frontals (Tyrannosaurus) *;30.Nasals, nasals form a relatively smooth contact with maxillae (Nanotyrannus) versus astrongly interdigitating contact with notches fitting into the maxillae (Tyrannosaurus) *;31.Nasals, nasals flat posteriorly (Nanotyrannus) or with a dorsal depression or groove, andlateral edges of nasals upturned to contribute to nasolacrimal ridge (Tyrannosaurus) †.Lacrimal32.Lacrimal, lacrimal L-shaped in lateral view, anterior and ventral rami diverging atapproximately a right angle (Nanotyrannus) or anterior and ventral rami diverging at anacute angle in lateral view (Tyrannosaurus) *;33.Lacrimal, anterior process similar to ventral process in length (Nanotyrannus) or anteriorprocess much shorter than ventral process (Tyrannosaurus) †;34.Lacrimal, lacrimal with a low, crescent-shaped lacrimal horn (Nanotyrannus) or lacrimalhorn reduced to a low, broad rugosity (Tyrannosaurus) †;35.Lacrimal, lacrimal horn mediolaterally narrow and with a narrow apex (Nanotyrannus) orstrongly inflated and a transversely broad, rounded apex (Tyrannosaurus) *;36.Lacrimal, lacrimal horn with a broad, strongly emarginated pneumatic excavation withmultiple large foramina (Nanotyrannus) versus reduced pneumatic excavation with a smallforamen (Tyrannosaurus) *;37.Lacrimal, broad development of antorbital fossa on base of lacrimal ventral ramus(Nanotyrannus) versus anteroposteriorly narrow exposure of antorbital fossa (Tyrannosaurus);38.Lacrimal, orbital bar strongly curved (Nanotyrannus) versus relatively straight(Tyrannosaurus) †;39.Lacrimal, bone T-shaped in lateral view, with a large posterior process (Nanotyrannus) orL-shaped, with a short posterior process (Tyrannosaurus) *;40.Lacrimal, lacrimal with low medial flange (Nanotyrannus) or prominent medial flange (Tyrannosaurus);41.Lacrimal, medial surface with a small foramen in antorbital fossa (Nanotyrannus) or enlarged pneumatic opening in the antorbital fossa (Tyrannosaurus);42.Lacrimal, large, shallow depression on medial surface of lacrimal (Nanotyrannus) or small deep fossa (Tyrannosaurus).Frontals 43. Frontals, frontals participate in orbital margin (Nanotyrannus) or excluded from orbit by postorbital-lacrimal contact (Tyrannosaurus) †;44.Frontals, frontal table long and narrow in dorsal view (Nanotyrannus) versus short and wide (Tyrannosaurus) †;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) †;46. 47.Frontals, supratemporal fossae short (Nanotyrannus) versus very long (Tyrannosaurus) *; Frontals, frontals broad anteriorly between lacrimals (Nanotyrannus) versus strongly constricted between lacrimals (Tyrannosaurus) †;48.Frontals, supratemporal fossa with a concave anterior margin (Nanotyrannus) or S-shaped margin of supratemporal fossae, being strongly extended forward medially (Tyrannosaurus);49.Frontals, distinct downflex of supratemporal fossae relative to frontal table absent (Nanotyrannus) or present, and supratemporal fossae distinctly sloped downward relative to (Tyrannosaurus) †;50.Frontals, frontal-postorbital suture shallow in lateral view (Nanotyrannus) or dorsoventrally extensive (Tyrannosaurus) †.Parietal 51. Parietal, nuchal crest in posterior view with pointed dorsolateral corners (Nanotyrannus) or broadly rounded (Tyrannosaurus);52.Parietal, posterior surface of nuchal crest with broad ridge (Nanotyrannus) or a sharp, narrow, well-defined ridge (Tyrannosaurus);53.Parietal, parietal nuchal crest straight in dorsal view (Nanotyrannus) or arcuate, projecting back along midline and wrapping forward laterally (Tyrannosaurus).Postorbital 54. Postorbital, postorbital with a rudimentary postorbital boss (Nanotyrannus), versus a massive, dorsoventrally extended postorbital boss (Tyrannosaurus) *;55.Postorbital, jugal process anteroposteriorly narrow (Nanotyrannus) versus anteroposteriorly broad (Tyrannosaurus) *;56.Postorbital, suborbital flange rudimentary (Nanotyrannus) versus expanded and constricting orbit (Tyrannosaurus) *;57.Postorbital, straight contact with the jugal (Nanotyrannus) versus jugal contact strongly convex (Tyrannosaurus) *;58.Postorbital, squamosal process narrow and splintlike (Nanotyrannus) or a dorsoventrally deep, triangular structure (Tyrannosaurus) *;59.Postorbital, main body of postorbital shallow (Nanotyrannus) or dorsally extended above squamosal process (Tyrannosaurus) *;60.Postorbital, anterior end of postorbital shallow (Nanotyrannus) or deep and massive where it contacts frontals and lacrimals (Tyrannosaurus) *;61.Postorbital, anterior end of postorbital projects anteriorly (Nanotyrannus) hooked downward anteriorly (Tyrannosaurus);62.Postorbital, fossa on medial surface of postorbital present (Nanotyrannus) or absent (Tyrannosaurus).Jugal 63. Jugal, antorbital fossa extends beneath lacrimal (Nanotyrannus) or lies largely anterior to ventral process of lacrimal (Tyrannosaurus) *;64.Jugal, body of jugal narrow anteriorly beneath lacrimal (Nanotyrannus) versus dorsoventrally expanded relative to depth beneath orbit (Tyrannosaurus) †;65.Jugal, jugal with a wide, shallowly concave orbital margin (Nanotyrannus) versus jugal contribution to orbit a deep, narrow notch (Tyrannosaurus) *;66.Jugal, jugal with a small pneumatic opening at the corner of the antorbital fossa (Nanotyrannus) versus a large dorsally positioned one (Tyrannosaurus) *;67.Jugal, pneumatic recess shallow (Nanotyrannus) or deeply excavating the jugal (Tyrannosaurus) *;68.Jugal, notch for postorbital small (Nanotyrannus) or enlarged to receive a broad ventral process of the jugal (Tyrannosaurus) *;69.Jugal, postorbital process anteroposteriorly narrow where it contacts postorbital (Nanotyrannus) or anteroposteriorly broad (Tyrannosaurus);70.Jugal, narrow articulation for the postorbital (Nanotyrannus) or contacts postorbital via a broadly overlapping lap joint (Tyrannosaurus);71. 72.Jugal, quadratojugal ramus short (Nanotyrannus) versus elongate (Tyrannosaurus) †; Jugal, posterior ramus extends horizontally (Nanotyrannus) or dorsal margin deflected upwards (Tyrannosaurus) †.Quadratojugal73.Quadratojugal, forms an anteroposteriorly short contact with squamosal (Nanotyrannus) versus a broad squamosal contact (Tyrannosaurus);74.Quadratojugal, anterior process of quadratojugal narrow (Nanotyrannus) versus deep (Tyrannosaurus);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);77.Quadratojugal, pneumatic foramen pierces lateral surface of quadratojugal (Nanotyrannus) or pneumatic foramen absent (Tyrannosaurus) (autapomorphy);78.Quadratojugal, posterior process extends posteriorly (Nanotyrannus) or posterodorsally to wrap onto posterior face of quadrate (Tyrannosaurus);79.Quadrate, quadratojugal pneumatic foramen present (Nanotyrannus) or absent (Tyrannosaurus) †.Squamosals80.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);81.Squamosal, ventral fossa of squamosal bounded anteriorly by a narrow bar of bone (Nanotyrannus) or a broad, shallow shelf (Tyrannosaurus);82.Squamosal, anterior lamina does not extend forward (Nanotyrannus) or extends forward to anterior end of squamosal (Tyrannosaurus);83.Squamosal, ventral fossa lacks a pneumatic recess (Nanotyrannus) or pneumatic recess present in the roof of the ventral fossa (Tyrannosaurus);84.Squamosal, quadratojugal process forming a narrow point anteriorly (Nanotyrannus) or a broad rounded or subrectangular tip (Tyrannosaurs).Vomer85. 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).Palatine88.Palatine, dorsal process of palatine lacks posterior expansion (Nanotyrannus) or bears a large, broad posterior expansion (Tyrannosaurus);89.Palatine, neck of dorsal process projects anterodorsally (Nanotyrannus) or dorsally (Tyrannosaurus) *;90.Palatine, anterior prong of dorsal process long and slender (Nanotyrannus) or short and robust (Tyrannosaurus);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).Ectopterygoid94.Ectopterygoid, opening of pneumatic recess a thin slot (Nanotyrannus) or a large aperture (Tyrannosaurus);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 largepneumatic foramen (Tyrannosaurus);97.Ectopterygoid, ectopterygoid weakly expanded (Nanotyrannus) strongly inflated(Tyrannosaurus).Braincase98.Supraoccipital, subrectangular (Nanotyrannus) forked dorsally (Tyrannosaurus);99.Exoccipitals, paroccipital processes taper in posterior view (Nanotyrannus) or distally broad(Tyrannosaurus);100.Exoccipitals, paroccipital processes extend laterally (Nanotyrannus) versus posterolaterally(Tyrannosaurus);101.Parasphenoid, rostrum long, slender and triangular in lateral view (Nanotyrannus) orproportionately short, deep and rectangular in shape (Tyrannosaurus) *;102.Basioccipital with prominent depressions ventrolateral to the occipital condyle andextending onto the basal tubera in posterior view (Nanotyrannus) or absent (Tyrannosaurus);103.Basioccipital, basal tubera separated by a deep, narrow notch (Nanotyrannus) versus ashallow, wide notch (Tyrannosaurus);104.Basioccipital, basal tubera wider than basispterygoid processes and extremely wide relativeto skull width (Nanotyrannus) or as wide or narrower than basipterygoid processes(Tyrannosaurus) (autapomorphy);105.Basisphenoid, basisphenoid recess, faces posteroventrally (Nanotyrannus) or stronglydirected posteriorly (Tyrannosaurus).Dentary106.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 tomidlength (Tyrannosaurus);108.Dentary, symphysis weakly developed (Nanotyrannus) or massive facet where dentariescontact (Tyrannosaurus);109.Dentary, symphysis ends beneath fourth tooth (Nanotyrannus) or third (Tyrannosaurus);110.Dentary, interdental plates weakly developed, tapering dorsally (Nanotyrannus) or large andbroad, 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 bowedoutwards anteriorly in dorsal view to create a broad, U-shaped jaw (Tyrannosaurus);118.Dentary, weakly expanded posteriorly (Nanotyrannus) versus strongly expanded posteriorlyto about twice its minimum depth (Tyrannosaurus);119.Dentary, lingual bar similar in depth anteriorly and posteriorly (Nanotyrannus) versusnarrow 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 andU-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 angularprocess (Tyrannosaurus).Posterior Mandible124.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 heightsubequal (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 ofthe surangular (Tyrannosaurus);130.Surangular, shallow below surangular foramen (Nanotyrannus) versus very deep belowsurangular foramen (Tyrannosaurus);131.Surangular, long and low (Nanotyrannus) or short and deep (Tyrannosaurus) *;132.Surangular, coronoid process weakly developed (Nanotyrannus) or tall and anteroposteriorlyexpanded (Tyrannosaurus);133.Surangular, surangular shelf thin (Nanotyrannus) or thick and massive (Tyrannosaurus);134.Surangular, surangular foramen lies just anterior to condyle (Nanotyrannus) or well anteriorto condyle (Tyrannosaurus);135.Articular, subrectangular medial projection in caudal view (Nanotyrannus) or articularsmoothly rounded and semicircular to crescentic in posterior view (Tyrannosaurus).Dentition136.Dentition, premaxillary teeth procumbent (Nanotyrannus) or project vertically down(Tyrannosaurus) † (autapomorphy);137.Dentition, premaxillary tooth apices blunt and chisel-like (Nanotyrannus) versus sharp andpointed (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 tosuccessive 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 largeand 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 moreposterior teeth (Nanotyrannus) or caniniform teeth in anterior maxilla and dentary(Tyrannosaurus) †;Postcrania145.Scapula, broad shaft relative to coracoid articulation (Nanotyrannus) or narrow neck andvery 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 scapularfacet (Tyrannosaurus);147.Humerus, proximal head small and ellipsoidal (Nanotyrannus) or massive, bulbous, andproximally 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) orproportionately 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 ventraltubercle or ‘pillar’ (Tyrannosaurus);Body Size159.Small size (estimated skull length ≤ 90 cm) or large (>90 skull length);
description: Published as part of Longrich, Nicholas R. & Saitta, Evan T., 2024, Taxonomic Status of Nanotyrannus lancensis (Dinosauria: Tyrannosauroidea) - A Distinct Taxon of Small-Bodied Tyrannosaur, pp. 12-17 in Fossil Studies 2 (1) on page 12, DOI: 10.3390/fossils2010001, http://zenodo.org/record/10535269