Ankylosauridae

{{Short description|Extinct family of dinosaurs}} {{Automatic taxobox | name = Ankylosaurids | image = Euoplocephalus tutus RTMP.jpg | image_caption = Mounted skeleton of ''Scolosaurus thronus'', Royal Tyrrell Museum of Palaeontology | fossil_range = Early–Late Cretaceous, {{Fossil range|122|66|refs=<ref name=":0"/>}}{{period fossil range|Cretaceous|122|66}} | taxon = Ankylosauridae | authority = Brown, 1908 | type_species = {{extinct}}''Ankylosaurus magniventris'' | type_species_authority = Brown, 1908 | subdivision_ranks = Subgroups | subdivision = *{{extinct}}''Aletopelta'' *{{extinct}}''Cedarpelta'' *{{extinct}}''Chuanqilong'' *{{extinct}}''Huaxiazhoulong''<ref name="Huaxiazhoulong">{{Cite journal |last1=Zhu |first1=Ziheng |last2=Wu |first2=Jie |last3=You |first3=Yue |last4=Jia |first4=Yingli |last5=Chen |first5=Chujiao |last6=Yao |first6=Xi |last7=Zheng |first7=Wenjie |last8=Xu |first8=Xing |date=2024-11-08 |title=A new ankylosaurid dinosaur from the Upper Cretaceous of Jiangxi Province, southern China |journal=Historical Biology |language=en |pages=1–17 |doi=10.1080/08912963.2024.2417208 |issn=0891-2963}}</ref> *{{extinct}}''Liaoningosaurus'' *{{extinct}}''Maleevus''? *{{extinct}}'''Shamosaurinae''' <small>Tumanova, 1983</small> **{{extinct}}''Gobisaurus'' **{{extinct}}''Shamosaurus'' *{{extinct}}'''Ankylosaurinae''' | synonyms = *Syrmosauridae <small>Maleev, 1952</small> }}

'''Ankylosauridae''' ({{IPAc-en|ˌ|æ|ŋ|k|ɪ|l|oʊ|ˈ|s|ɔː|r|ɪ|d|iː}}) is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known ankylosaurids date to around {{Ma|122}}, and the clade went extinct {{ma|66}} during the Cretaceous–Paleogene extinction event.<ref name=":0">{{Cite book|title=Dinosaurs: A Concise Natural History|last1=Fastovsky|first1=David E.|last2=Weishampel|first2=David B.|publisher=Cambridge University Press|year=2012|edition=2nd|location=Cambridge}}</ref> These animals were mainly herbivorous and were obligate quadrupeds, with leaf-shaped teeth and robust, scute-covered bodies. Ankylosaurids possess a distinctly domed and short snout, wedge-shaped osteoderms on their skull, scutes along their torso, and a tail club.<ref name=":1">{{Cite journal|last=Sereno|first=Paul C.|date=1999-06-25|title=The Evolution of Dinosaurs|journal=Science|language=en|volume=284|issue=5423|pages=2137–2147|doi=10.1126/science.284.5423.2137|issn=0036-8075|pmid=10381873}}</ref>

Ankylosauridae is exclusively known from the Northern Hemisphere, with specimens found in North America, Europe, and Asia. The first discoveries within this family were of the genus ''Ankylosaurus'', by Peter Kaiser and Barnum Brown in Montana in 1906.<ref name=":2">{{Cite journal|last1=Barnum.|first1=Brown|last2=C.|first2=Kaisen, Peter|date=1908-01-01|title=The Ankylosauridae, a new family of armored dinosaurs from the Upper Cretaceous. Bulletin of the AMNH; v. 24, article 12.|language=en-US|hdl=2246/1435}}</ref> Brown went on to name Ankylosauridae and the subfamily '''Ankylosaurinae''' in 1908.

== Anatomy == [[File:Ankylosaurus tail terminology.png|thumb|left|''Dyoplosaurus'' tail reconstruction, showing terms used for parts of ankylosaurid tails]] Ankylosaurids are stout, solidly built, armoured dinosaurs. They possess accessory ossifications on cranial bones that cover some skull openings and form wedge-shaped, horn-like structures. Along the ankylosaurid torso are scute rows, which are filled in with smaller ossicles to create a fused shield of armour.<ref name=":1" /> Only two collars of armour plates can be found on the neck, as opposed to the sister group, nodosaurids, which have three.<ref name=":0" /> Nodosauridae and Ankylosauridae also share the unique attribute of abundant structural fibres in both primary and secondary bone.<ref>{{Cite journal|last1=Stein|first1=Martina|last2=Hayashi|first2=Shoji|last3=Sander|first3=P. Martin|date=2013-07-24|title=Long Bone Histology and Growth Patterns in Ankylosaurs: Implications for Life History and Evolution|journal=PLOS ONE|volume=8|issue=7|article-number=e68590|doi=10.1371/journal.pone.0068590|issn=1932-6203|pmc=3722194|pmid=23894321|bibcode=2013PLoSO...868590S |doi-access=free}}</ref> Ankylosaurids also have an S-shaped narial passage.<ref name=":0" />

The most distinguishing feature of ankylosaurids is the presence of a tail club. It is made out of modified interlocking distal caudal vertebrae and enlarged, bulbous osteoderms.<ref name=":3">{{Cite journal|last1=Arbour|first1=Victoria M.|last2=Currie|first2=Philip J.|date=2015-10-01|title=Ankylosaurid dinosaur tail clubs evolved through stepwise acquisition of key features|journal=Journal of Anatomy|language=en|volume=227|issue=4|pages=514–523|doi=10.1111/joa.12363|issn=1469-7580|pmc=4580109|pmid=26332595}}</ref> The "handle" of the tail club involves the vertebrae, and requires elongated prezygapophyses to overlap at least half of the preceding vertebral centrum length.<ref name=":3" /> These distal caudal vertebrae also lack transverse processes and neural spines, and therefore tend to be longer than they are wide; the reverse is true for proximal caudal vertebrae.<ref name=":3" /> Derived ankylosaurids possess a fusion of posterior dorsal, sacral, and sometimes anterior caudal vertebrae, which forms a singular structure called a "synsacrum complex". There is a complete fusion between centra, neural arches, zygapophyses, and sometimes neural spines.<ref name=":4">{{Cite journal|last=Coombs |first=Walter P. Jr.|date=1995-07-01|title=Ankylosaurian tail clubs of middle Campanian to early Maastrichtian age from western North America, with description of a tiny club from Alberta and discussion of tail orientation and tail club function|journal=Canadian Journal of Earth Sciences|volume=32|issue=7|pages=902–912|doi=10.1139/e95-075|bibcode=1995CaJES..32..902C |issn=0008-4077}}</ref>

In 2017, Victoria M. Arbour and David C. Evans described a new genus of ankylosaurine that preserved extensive soft tissues along the body. This animal, named ''Zuul'' after its resemblance to the ''Ghostbusters'' monster, is also the first ankylosaur from the Judith River Formation.<ref>{{Cite news|url=https://www.smithsonianmag.com/science-nature/ankylosaur-could-really-make-your-ankles-sore-180963204/|title=Introducing 'Zuul,' an Ankylosaur That Could Really Make Your Ankles Sore|last=Switek|first=Brian|date=2017-05-08|work=Smithsonian|access-date=2018-01-15|language=en}}</ref>

== History of study == [[File:Skull_of_Ankylosaurus.jpg|left|thumb|Skull of first known ankylosaurid specimen, belonging to ''Ankylosaurus'']] Barnum Brown and Peter Kaisen discovered the first ankylosaurid genus, ''Ankylosaurus'', in 1906 in the Hell Creek Beds in Montana.<ref name=":2" /> The fossil material they found was a portion of the skull, two teeth, some vertebrae, a distorted scapula, ribs and more than thirty osteoderms.<ref name=":2" /> Reconstruction of the specimen was initially met with skepticism by those who believed it to be at least very close to, or completely a part of the genus ''Stegopelta'', and Brown himself placed it within the suborder Stegosauria.<ref name=":2" />

It has previously been interpreted that variation in ankylosaurid tail club shape is due to sexual dimorphism, which assumes that tail club morphology has a sex-linked intraspecific function.<ref name=":4" /> This is possible if the tail club was used for agonistic behaviour. However, a sexual dimorphism theory would predict roughly equal numbers of individuals with two distinct sizes of tail clubs. Obvious sexual dimorphism has not been documented, but if the clubs of one sex are much larger, then there would be a bias for preservation and discovery towards that sex.<ref name=":4" /><ref name=":5">{{Cite journal|last=M|first=Arbour, Victoria|title=Systematics, evolution, and biogeography of the ankylosaurid dinosaurs|url=https://era.library.ualberta.ca/files/6d56zx896#.V04Gy_krLIU|publisher=University of Alberta Libraries: Education and Research Archive|date=June 2014|doi=10.7939/R31N7XW06 }}</ref>

==Phylogeny== [[File:AnkylosaurCMNClub.jpg|thumb|Club of indeterminate ankylosaurine, CMN 349]] In 1978, W.P. Coombs, Jr. classified almost all valid species of Ankylosauria within either Nodosauridae or Ankylosauridae.<ref>{{Cite journal|last=Coombs |first=W.P. Jr.|date=1978|title=The Families of the Ornithischian Dinosaur Order Ankylosauria|journal=Palaeontology|pages=143–70}}</ref> This was a pivotal study and described many characters of ankylosaurs in the earliest phylogenetic analyses of the group.

Later in 1998, Paul Sereno formally defined Ankylosauridae as all ankylosaurs more closely related to ''Ankylosaurus'' than to ''Panoplosaurus''.<ref>{{Cite journal|last=Sereno|first=Paul|date=1998|title=A Rationale for Phylogenetic Definitions, with Application to the Higher-level Taxonomy of Dinosauria|journal=Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen|pages=41–83|doi=10.1127/njgpa/210/1998/41}}</ref> Ankylosaurs not known to possess a tail club were included in Kenneth Carpenter's 2001 phylogeny of Ankylosauridae.<ref>{{Cite book|title=The Armored Dinosaurs|last=Carpenter|first=K|publisher=Indiana University Press|year=2001|editor-last=Carpenter|editor-first=K|pages=455–483|chapter=Phylogenetic Analysis of Ankylosauria}}</ref> Daniel Madzia and colleagues in 2021 formally defined Ankylosauridae in the ''PhyloCode'' as "the largest clade containing ''Ankylosaurus magniventris'', but not ''Nodosaurus textilis''".<ref name="madzia2021">{{cite journal|last1=Madzia|first1=D.|last2=Arbour|first2=V.M.|last3=Boyd|first3=C.A.|last4=Farke|first4=A.A.|last5=Cruzado-Caballero|first5=P.|last6=Evans|first6=D.C.|year=2021|title=The phylogenetic nomenclature of ornithischian dinosaurs|journal=PeerJ|volume=9|article-number=e12362|doi=10.7717/peerj.12362|pmid=34966571|pmc=8667728 |doi-access=free }}</ref> The basal subfamily '''Shamosaurinae''' is formally defined as "the largest clade containing ''Gobisaurus domoculus'' and ''Shamosaurus scutatus'', but not ''Ankylosaurus magniventris''".<ref name="madzia2021"/> This definition ensures that Shamosaurinae is only valid when both ''Gobisaurus'' and ''Shamosaurus'' form a clade to the exclusion of ''Ankylosaurus''.<ref name="madzia2021"/> In a study done in 2004 by Vickaryous et al., ''Gargoyleosaurus'', ''Gastonia,'' and ''Minmi'' were recorded as basal ankylosaurids, with the rest of the ankylosaurids filled out with ''Gobisaurus'', ''Shamosaurus'', and ankylosaurines from China, Mongolia, and North America.<ref>{{Cite book|title=Ankylosauria|last1=Vickaryous|first1=Matthew K.|last2=Maryanska|first2=Teresa|author-link2 = Teresa Maryańska|last3=Weishampel|first3=David B.|pages=363–392|doi=10.1525/california/9780520242098.003.0020|isbn=978-0-520-94143-4|publisher=University of California Press|date=2004-06-12}}</ref>

In 2012, Thompson et al. undertook an analysis of almost all known valid ankylosaurs and outgroup taxa at the time.<ref name=":6">{{Cite journal|last1=Thompson|first1=Richard S.|last2=Parish|first2=Jolyon C.|last3=Maidment|first3=Susannah C. R.|last4=Barrett|first4=Paul M.|date=2012-06-01|title=Phylogeny of the ankylosaurian dinosaurs (Ornithischia: Thyreophora)|journal=Journal of Systematic Palaeontology|volume=10|issue=2|pages=301–312|doi=10.1080/14772019.2011.569091|s2cid=86002282|issn=1477-2019}}</ref> They based their resulting phylogeny on characters representing cranial, post-cranial, and osteodermal anatomy, and details of synapomorphies for each recovered clade. This study placed ''Gargoyleosaurus'' and ''Gastonia'' within basal Nodosauridae, and put ''Cedarpelta'' and ''Liaoningosaurus'' as basal ankylosaurids.<ref name=":6" /> {{clade| style=font-size:100%;line-height:80% |1={{clade |1={{clade |1=''Huayangosaurus taibaii'' |2=''Stegosaurus armatus'' }} |2={{clade |1=Nodosauridae |label2='''Ankylosauridae''' |2={{clade |1=''Minmi paravertebra'' |2={{clade |1=''Liaoningosaurus paradoxus'' |2={{clade |1=''Cedarpelta bilbeyhallorum'' |2={{clade |1=''Gobisaurus domoculus'' |2={{clade |1=''Shamosaurus scutatus'' |2={{clade |1=''Zhongyuansaurus luoyangensis'' |2=''Tsagantegia longicranialis'' |3={{clade |1={{clade |1=''Shanxia tianzhensis'' |2={{clade |1=''"Crichtonsaurus" benxiensis'' |2={{clade |1=''Dyoplosaurus acutosquameus'' |2=''Pinacosaurus mephistocephalus'' }} }} }} |2={{clade |1={{clade |1=''Ankylosaurus magniventris'' |2=''Euoplocephalus tutus'' }} |2={{clade |1={{clade |1=''Minotaurasaurus ramachandrani'' |2=''Pinacosaurus grangeri'' }} |2={{clade |1=''Nodocephalosaurus kirtlandensis'' |2={{clade |1={{clade |1=''Talarurus plicatospineus'' |2=''Tianzhenosaurus youngi'' }} |2={{clade |1=''Saichania chulsanensis'' |2=''Tarchia gigantea'' }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} [[File:Gastonia_fossil.jpg|thumb|''Gastonia'' and other polacanthine dinosaurs have uncertain placement, possibly within Ankylosauridae]] In 2016, Arbour and Currie have presented a phylogenetic analysis of Ankylosauridae consisting of ''Gastonia'', ''Cedarpelta'', ''Chuanqilong'', other basal ankylosaurids, and a number of derived ankylosaurids. Their phylogeny includes some uncertain phylogenetic relationships, between ''Ankylosaurus'', ''Anodontosaurus'', ''Scolosaurus'', and ''Ziapelta''.<ref name=":10">{{Cite journal|last1=Arbour|first1=Victoria M.|last2=Currie|first2=Philip J.|date=2016-05-03|title=Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs|journal=Journal of Systematic Palaeontology|volume=14|issue=5|pages=385–444|doi=10.1080/14772019.2015.1059985|s2cid=214625754|issn=1477-2019}}</ref> {{clade| style=font-size:100%;line-height:80% |1={{clade |1=''Lesothosaurus'' |2={{clade |1=''Scelidosaurus'' |label2=Thyreophora |2={{clade |1=Stegosauria |label2=Ankylosauria |2={{clade |1=''Minmi paravertebra'' |2={{clade |label1=Nodosauridae |1={{clade |1=''Gargoyleosaurus'' |2=More derived nodosaurids }} |label2='''Ankylosauridae''' |2={{clade |1={{clade |1=''Gastonia'' |2=''Ahshislepelta'' }} |2={{clade |1=''Aletopelta'' |2=''Liaoningosaurus'' |3={{clade |1=''Cedarpelta'' |2=''Chuanqilong'' }} |4={{clade |1={{clade |1=''Gobisaurus'' |2=''Shamosaurus'' }} |2={{clade |1=''Crichtonpelta'' |2={{clade |1=''Tsagantegia'' |2=''"Zhejiangosaurus"'' |3={{clade |1=''Pinacosaurus grangeri'' |2=''Pinacosaurus mephistocephalus'' }} |4={{clade |1={{clade |1=''Saichania'' |2={{clade |1=''Tarchia'' |2=''Zaraapelta'' }} }} |2={{clade |1=''Dyoplosaurus'' |2={{clade |1={{clade |1=''Talarurus'' |2=''Nodocephalosaurus'' }} |2={{clade |1={{clade |1=''Ankylosaurus'' |2=''Anodontosaurus'' }} |2=''Euoplocephalus'' |3={{clade |1=''Scolosaurus'' |2=''Ziapelta'' }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }}

== Paleobiology ==

=== Posture and locomotion === Ankylosaurids were likely very slow-moving animals. In all Ankylosauria, the fibula is more slender than the tibia, suggesting that the tibia carried most of the weight of the animal, while the fibula served as an area of muscular attachment.<ref name=":8">{{Cite journal|last=Coombs |first=W.P. Jr|date=1979|title=Osteology and Myology of the Hindlimb in the Ankylosauria (Reptilia, Ornithischia)|jstor=1304004|journal=Journal of Paleontology|pages=666–684|volume=53|issue=3}}</ref> Hindlimb muscles of ''Euoplocephalus'' have been restored and the placement of several muscles inserting on the femur have very short moment arms. Muscles inserting on the tibia and fibula have longer moment arms. This pattern of retractor muscles points to an elephantine locomotion, consistent with columnar posture.<ref name=":8" />

Restoration of ''Euoplocephalus'' forelimbs demonstrate similarities to crocodilian forelimb musculature.<ref name=":9">{{Cite journal|last=Coombs|first=Walter P.|date=1978-01-01|title=Forelimb Muscles of the Ankylosauria (Reptilia, Ornithischia)|jstor=1303969|journal=Journal of Paleontology|volume=52|issue=3|pages=642–657}}</ref> The most well developed muscles in the pectoral region had more of a weight-bearing function than a rotational one. It has also been postulated that the carpals and metacarpals bear resemblance to those of tetrapods with fossorial (burrowing) habits.<ref name=":9" />

Several muscles in the posterior of ankylosaurids (dorsalis caudae, ilio-caudalis, coccygeo-femoralis brevis, coccygeo-femoralis longus, ilio-tibialis, and ischio caudalis) were used for motion of the tail and tail club.<ref name=":8" /> Ankylosaurids tend to have horizontal rather than an obliquely vertical orientation of zygapophyseal articulations in the free caudal vertebrae of the tail. This arrangement is most effective for side-to-side rather than vertical mobility.<ref name=":4" /> The absence of musculature to elevate the tail, and this orientation of zygapophyses suggest that the tail and its club swept parallel to and slightly above the ground.<ref name=":4" />

=== Biogeography === thumb|450px|Map of ankylosaurine distribution across North America in the Late Cretaceous It is difficult to establish the geographical origin of Ankylosauridae at present. There is a mix of basal ankylosaurids from both North America and Asia, which carries on through accepted cladistic analyses.<ref>{{Cite web|url=https://pseudoplocephalus.com/2015/08/23/know-your-ankylosaurs-everybodys-in-this-together-edition/|title=Know Your Ankylosaurs: Everybody's in this Together Edition|last=Arbour|first=Victoria|date=August 23, 2015|website=Pseudoplocephalus}}</ref> It appears that in the mid-Cretaceous, Asian nodosaurids were replaced by ankylosaurine ankylosaurids.<ref name=":10"/> Some researchers postulate that Ankylosaurines migrated into North America from Asia between the Albian and Campanian, where they diversified into a clade of ankylosaurines characterized by arched snouts and flat cranial bone plates (caputegulae).<ref name=":10" /> There is no evidence for ankylosaurids in Gondwana.<ref name=":10" />

=== Variation === Within Ankylosauridae there is much individual and interspecific variation in expression of armour. However, the most researched aspect of ankylosaurid armour is the tail club. There has been substantial ontogenetic and individual variability found in the morphology of this feature. There have been at least 16 caudal vertebrae included in the handle of the tail club of ''Pinacosaurus grangeri'', and ''Euoplocephalus'' has an estimated 9 – 11 coossified caudals.<ref name=":4" />

Variations in tail knob shape, thickness, and length are attributed to individual variation, taxonomy, or representation of different growth phases.<ref name=":4" /> There are difficulties with this last aspect, however, in that known clubs do not conform to a single growth series, yet some differences must be ontogenetic and allometric.<ref name=":4" /><ref name=":5" />

=== Lifestyle === Most ankylosaurid teeth were leaf-shaped, implying a mainly herbivorous diet. Their teeth could be smooth or fluted, or may differ on labial and lingual surfaces.<ref name=":11">{{Cite book|title=Dinosaur Systematics: Approaches and Perspectives|last1=Carpenter|first1=Kenneth|last2=Currie|first2=Philip J.|publisher=Cambridge University Press|year=1990}}</ref> ''Euoplocephalus tutus'' possess ridges and grooves on their teeth that have no relation to their marginal cusps.<ref name=":11" /> With their downward-facing neck and head, it is plausible for ankylosaurids to feed in a grazing pattern.<ref name=":0" />

Non-herbivorous habits have been implicated for some species, however. ''Pinacosaurus'' has been speculated as being an ant-eater-like long tongued insectivore,<ref>Hill, R., D'Emic, M., Bever, G., Norell, M. 2015. A complex hyobranchial apparatus in a Cretaceous dinosaur and the antiquity of avian paraglossalia. Zoological Journal of the Linnean Society. doi: 10.1111/zoj.12293</ref> while ''Liaoningosaurus'' has been proposed to be a piscivore. Either would be exceptional evidence of carnivory among ornithischians. thumb|Diagram showing ankylosaurid skull anatomy There are a few prevailing theories for ankylosaurid tail club function. The first is agonistic behaviour within a species.<ref name=":4" /> In most vertebrates, including dinosaurs, this behaviour is accompanied by structures for display or combat. Some researchers believe this phenomenon would have been implausible considering there is no modern tetrapod analogue that uses the tail for this purpose. These paleontologists instead propose that ankylosaurids made use of their broad, flat skull for head-butting between individuals.<ref name=":4" />

The second theory for tail club function is for defense against predators. It has been postulated that the club would be most effective against the metatarsals of an attacking theropod.<ref name=":4" /><ref name=":8" />

The bones that form cranial ornamentation have physiological costs, and so would be inefficient to produce merely for protection against predation. The theory has therefore been posed that these wedge-shaped osteoderms could support a partly sexually selected interpretation.<ref name=":5" />

==Timeline of genera==

<timeline> ImageSize = width:800px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px

Period = from:-201 till:-45 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:10 start:-200 ScaleMinor = unit:year increment:1 start:-201 TimeAxis = orientation:hor AlignBars = justify

Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:jurassic value:rgb(0.2,0.7,0.79) id:earlyjurassic value:rgb(0,0.69,0.89) id:middlejurassic value:rgb(0.52,0.81,0.91) id:latejurassic value:rgb(0.74,0.89,0.97) id:cretaceous value:rgb(0.5,0.78,0.31) id:earlycretaceous value:rgb(0.63,0.78,0.65) id:latecretaceous value:rgb(0.74,0.82,0.37) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:NAM3 bar:NAM4 bar:NAM5 bar:NAM6 bar:NAM7 bar:NAM8 bar:NAM9 bar:NAM10 bar:NAM11 bar:NAM12 bar:NAM13 bar:NAM14 bar:NAM15 bar:NAM16 bar:NAM17 bar:NAM18 bar:NAM19 bar:NAM20 bar:NAM21 bar:NAM22 bar:NAM23 bar:NAM24 bar:space bar:period bar:space bar:era

PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -201 till: -174 color:earlyjurassic text:Early from: -174 till: -163 color:middlejurassic text:Middle from: -163 till: -145 color:latejurassic text:Late from: -145 till: -100 color:earlycretaceous text:Early from: -100 till: -66 color:latecretaceous text:Late

bar:eratop from: -201 till: -145 color:jurassic text:Jurassic from: -145 till: -66 color:cretaceous text:Cretaceous

PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left

color:cretaceous bar:NAM1 from:-122 till:-120 text:Liaoningosaurus color:cretaceous bar:NAM2 from:-119 till:-113 text:Minmi color:cretaceous bar:NAM3 from:-113 till:-110 text:Shamosaurus color:cretaceous bar:NAM4 from:-108.5 till:-108 text:Cedarpelta color:cretaceous bar:NAM5 from:-105 till:-100 text:Zhongyuansaurus color:cretaceous bar:NAM6 from:-98 till:-83 text:Talarurus color:cretaceous bar:NAM7 from:-98 till:-83 text:Tsagantegia color:cretaceous bar:NAM8 from:-92 till:-90 text:Gobisaurus color:cretaceous bar:NAM9 from:-80 till:-79 text:Minotaurasaurus color:cretaceous bar:NAM10 from:-80 till:-75 text:Pinacosaurus color:cretaceous bar:NAM11 from:-76.5 till:-76 text:Scolosaurus color:cretaceous bar:NAM12 from:-76.5 till:-76 text:Dyoplosaurus color:cretaceous bar:NAM13 from:-76.4 till:-75.5 text:Euoplocephalus color:cretaceous bar:NAM14 from:-76.2 till:-75.2 text:Zuul color:cretaceous bar:NAM15 from:-76 till:-75 text:Nodocephalosaurus color:cretaceous bar:NAM16 from:-76 till:-74 text:Ahshislepelta color:cretaceous bar:NAM17 from:-75 till:-74 text:Aletopelta color:cretaceous bar:NAM18 from:-75 till:-74 text:Tianzhenosaurus color:cretaceous bar:NAM19 from:-75 till:-74 text:Shanxia color:cretaceous bar:NAM20 from:-74 till:-73 text:Oohkotokia color:cretaceous bar:NAM21 from:-72.8 till:-67 text:Anodontosaurus color:cretaceous bar:NAM22 from:-70 till:-69 text:Saichania color:cretaceous bar:NAM23 from:-70 till:-69 text:Tarchia color:cretaceous bar:NAM24 from:-66.5 till:-66 text:Ankylosaurus

PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25

bar:period from: -201 till: -174 color:earlyjurassic text:Early from: -174 till: -163 color:middlejurassic text:Middle from: -163 till: -145 color:latejurassic text:Late from: -145 till: -100 color:earlycretaceous text:Early from: -100 till: -66 color:latecretaceous text:Late

bar:era from: -201 till: -145 color:jurassic text:Jurassic from: -145 till: -66 color:cretaceous text:Cretaceous

</timeline>

==See also== {{Portal|Dinosaurs}} * Timeline of ankylosaur research

==References== {{Reflist|30em|refs=}}

*''Dinosaurs and other Prehistoric Creatures'', edited by Ingrid Cranfield (2000), Salamander books, pg. 250–257. * {{cite book|title=The Armored Dinosaurs|year=2001|chapter=Phylogenetic analysis of the Ankylosauria|editor=Carpenter, Kenneth|author =Carpenter K|pages=455&ndash;484|publisher=Indiana University Press|isbn=978-0-253-33964-5}} * Kirkland, J. I. (1996). Biogeography of western North America's mid-Cretaceous faunas - losing European ties and the first great Asian-North American interchange. J. Vertebr. Paleontol. 16 (Suppl. to 3): 45A

==External links== *[http://tolweb.org/tree?group=Ankylosauridae&contgroup=Ankylosauria Family Tree] *[http://tolweb.org/Ankylosauridae Ankylosauridae] Tree of Life web project *[https://pseudoplocephalus.com/ Pseudoplocephalus], Blog by an evolutionary biologist and vertebrate palaeontologist specializing in ankylosaurs

{{Thyreophora|A.}} {{Taxonbar|from=Q517099}}

Category:Ankylosauridae Category:Dinosaur families Category:Cretaceous dinosaurs