type specimen amnh 5251
the first remains of anchiceratops discovered along red deer river in canadian province of alberta in 1912 expedition led barnum brown. holotype, specimen amnh 5251, half of skull, including long frill, , 2 other partial skulls, specimens amnh 5259 (the paratype) , amnh 5273, found @ same time, stored in american museum of natural history in new york city. complete skull designated nmc 8535, discovered charles m. sternberg @ morrin in 1924, , described a. longirostris 5 years later, in 1929. species considered junior synonym of a. ornatus today. in total, @ least ten incomplete skulls have been recovered. skulls different respect proportions (e.g. size of supraorbital horn cores, dimensions of frill) had led researchers conclude disparity result of interspecific differences or due sexual dimorphism.
the genus name anchiceratops, means near horned face , , derived greek words anchi (αγχι-) meaning near , keras (κερας) meaning horn , , ops (ωψ) meaning face . anchiceratops described , named american paleontologist barnum brown, in 1914, believed dinosaur represented transitional form closely related both monoclonius , triceratops , intermediate between them, closest in development of skull frill latter, hence generic name meaning near ceratops . type , valid species known today anchiceratops ornatus, name refers ornate margin of frill.
another specimen, nmc 8547 (or cmn 8547) collected sternberg in 1925, lacks skull otherwise complete skeleton known ceratopsid, preserving complete spinal column down last tail vertebra. sternberg s material housed in canadian museum of nature in ottawa. nmc 8547 displayed half-mount better preserved right side showing, , completed cast skull replica of nmc 8535. other material has been found since, including 1 or 2 possible bonebed deposits in alberta, little anchiceratops material has been described.
nmc 8547 mounted @ canadian museum of nature, completed skull cast of nmc 8535. nmc 8547 might represent separate taxon
most anchiceratops fossils have been discovered in horseshoe canyon formation of alberta, belongs later part of campanian stage of late cretaceous period (anchiceratops remains known lower part of formation, , range in age between 72.5-71 million years ago). frill fragments found in maastrichtian almond formation of wyoming in united states resemble anchiceratops. however, brown horn fragments (specimens nmc 9590 , 10645) , frill pieces (specimina nmc 9813, 9814 , 9829) have been found 2 localities in older oldman , dinosaur park formations (late campanian, 76.5-75 million years ago) characteristic pattern of points seen in anchiceratops frills. these may represent records of a. ornatus or possibly second, related species. anchiceratops remains recovered in terrestrial sediments st. mary river formation @ scabby butte locality in southwestern alberta, however, fossils cannot referred specific species.
in 2012, mallon concluded many more anchiceratops fossils had been collected had been realised. these included specimens tmp 1983.001.0001, complete skull of juvenile; uw 2419, complete skull; rom 802, skull lacking snout; fmnh p15003, upper side of skull lacking snout; cmn 11838, left skull frill; cmn 12-1915, frill fragments; , ualvp 1618, rear edge of frill. larger number of fossils can examined statistical analysis solve long-standing controversies genus.
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