Talk:Polacanthus

image

Be niec to get a new one, didn't want this one in the taxobox Cas Liber 21:32, 14 June 2006 (UTC)

Polacanthus' head

"Early depictions often gave it a very vague head as it was only known from the rear half of the creature."

Is this to say that we've found its head since then? Or just that we now know what its front end would probably look like, based on similar animals? 71.217.98.158 03:42, 23 February 2007 (UTC)

Unfortunately, we don't have the head of Polacanthus yet, although there's a braincase that might go to it, and at least part of the skull is known for several ankylosaurians, including the probably related Gargoyleosaurus, Gastonia, and Hylaeosaurus, so we can make a much better educated guess than could be done several decades ago. J. Spencer 04:30, 23 February 2007 (UTC)

I'm suggesting that Polacanthus had a small head, asuming this by seeing Walking With Dinosaurs.--Dinonerd4488 (talk) 20:16, 27 August 2010 (UTC)

• A related issue, I noticed that this model[1] has horns on the head, but wasn't this absent in nodosaurs? MWAK?

FunkMonk (talk) 06:42, 17 June 2015 (UTC)

Very good question :o). Indeed nodosaurids typically had small squamosal bosses, compared to the sometimes "diabolical" horns of ankylosaurids. Minotaurasaurus e.g. was named for them. However, nodosaurids often have large posterior supraorbital horns (earlier often seen as postorbital horns). Sometimes they have real squamosal horns (Europelta e.g.). A complicating issue is whether Polacanthus was a nodosaurid in the first place. There are several competing hypotheses regarding the position of such basal forms (a grade of basal Ankylosauria, a clade of basal Ankylosauria, a grade/clade of basal ankylosaurids, a grade/clade of basal nodosaurids, grades of both ankylosaurids and nodosaurids etc.)

Personally I think the head shown was modelled after Gargoyleosaurus.--MWAK (talk) 13:17, 17 June 2015 (UTC)

So I guess it is alright? Scelidosaurus also seems to have had some kind of horns, or are they only on the neck? FunkMonk (talk) 17:51, 17 June 2015 (UTC)

It's a defensible choice and if anything more original than giving it some Sauropelta-like skull. The horns on some exemplars of Scelidosaurus are squamosal horns and pretty big too, one of the reasons Carpenter was convinced it was a basal ankylosaurid.--MWAK (talk) 18:49, 17 June 2015 (UTC)

Now we're at it, I was thinking of giving this image[2] an artistic overhaul, any suggestions to how it could be improved anatomically? FunkMonk (talk) 18:51, 17 June 2015 (UTC)

There are some points of attention:

1. Blows (2014) describes additional skull material. Among it large triangular jugal horns below the orbit.
2. No cervical halfrings seem to be present (so in this respect the image is correct as it is).
3. The exact position of the largest osteoderms is contentious. You might put them on the tail or on the back. Or both. In any case they are pretty big. They have these strangely tapering very long points. In the present image they are too short and far too blunt. Their bases were large too and their apparent size seen from the side would incorporate a base and a spike component. The last alone should equal about 70% of lower leg length. Or perhaps a third longer taking a horn sheath into account.
4. Blows (2014) suggests a double vertical dorsal row and a combination of splates and spikes along the rump side.
5. The lower leg was relatively long as correctly shown by your picture. It was also everted, by an outside rotation of the tibia around its axis. I'm not sure whether you already took that into account.
6. Foot claws were big, long and broad, and would visibly protrude. Four toes were probably present in the foot.--MWAK (talk) 20:24, 17 June 2015 (UTC)

• Thanks, it's the first "proper" ankylosaur I've drawn so far, so I'd like it to be accurate before I go on to the next one... You seem to be our resident ankylosaur expert, very handy, especially since theropods usually get all the attention. FunkMonk (talk) 07:02, 18 June 2015 (UTC)

Well, User:Anky-man is a real expert. I just refreshed some old knowledge when during the winter I completed the Dutch ankylosaurid articles. Success with your artwork!--MWAK (talk) 12:30, 18 June 2015 (UTC)

Oh, I didn't know he was still around (or well, not since 2012), he uploaded some pictures of rare specimens... FunkMonk (talk) 13:39, 18 June 2015 (UTC)

Fair use rationale for Image:Polacanthus.JPG

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BetacommandBot 00:43, 27 September 2007 (UTC)

Name origin

I looked through the second edition of The Dinosauria and couldn't find any support for the first two referrences:

"Genus authority given as Huxley, 1867 in some sources, such as the second edition of The Dinosauria."

"Species authority given as Hulke, 1881 in some sources, such as the second edition of The Dinosauria."

The 1881 description by Hulke attributes the suggestion of both the origin of the genus and species to a comment by Owen:

https://royalsocietypublishing.org/doi/epdf/10.1098/rstl.1881.0015

"The  remains  of Polacanthus were  found  by  Mr.  Fox  in  1865  in  a  bed  of  blue  shaly clay,  which  occurs  near the middle  of  the  cliff,  a  short  distance  east  of  Barne’s  Chine. The  bed  is  easily recognisable  by  the  large  quantities  of  lignite  which  it  contains.

Professor  R. Owen, to  whom  Mr.  Fox  showed  some  of  these  fossils  soon  after their discovery,  suggested  for the  animal indicated  by  them  the  name Polacanthus—many- spined—P. Foxii,  and  this  name  Mr.  Fox  adopted  in  an  account  of  his  discovery read by him at  the  next meeting  of the British Association.    A brief notice  of the discovery with  a rude  woodcut  also  appeared  about  the  same  time  in  the  “ Illustrated  London News.”   Both  these  communications  have  only  the  value  of  preliminary  notices  by persons without  anatomical  training,  and  no  description  of  the  fossils  sufficient for the use  of  palaeontologists  has yet  appeared.

Mr.  Fox’s  MS., read at the  meeting  of the British Association, cannot  now  be  found, and  his  paper  does  not  appear in the  “Reports.”    An  abstract  which  I  made  of  it in 1869  gives the following  list  of  the  parts  he  believed  he  had  secured..."

We should probably either attribute both the genus and species to Owen in 1865 or alternatively both the genus and species to Hulke 1881. I updated the second reference to this reference as it is more useful than a reference to a 1000+ page book without a page reference.

Any thoughts on the proper date for the species and/or genus name? Or even better a page number in The Dinosauria where the genus authority is given as Huxley 1867? DinoGarret (talk) 21:43, 7 July 2023 (UTC)