💾 Archived View for 80h.dev › agena › gopherpedia.com › 0 › Cetiosauriscus captured on 2020-10-31 at 00:51:00.
-=-=-=-=-=-=-
======================================================================
= Cetiosauriscus =
======================================================================
Introduction
======================================================================
'Cetiosauriscus' ( ) is a genus of sauropod dinosaur that lived
between 166 and 164 million years ago during the Callovian (Middle
Jurassic Period) in what is now England. A herbivore, 'Cetiosauriscus'
had—for sauropod standards—a moderately long tail, and longer
forelimbs, making them as long as its hindlimbs. It has been estimated
as about 15 m long and between 4 and in weight.
The only known fossil includes most of the rear half of a skeleton as
well as a hindlimb (NHMUK R3078). Found in Cambridgeshire in the
1890s, it was described by Arthur Smith Woodward in 1905 as a new
specimen of the species 'Cetiosaurus leedsi'. This was changed in
1927, when Friedrich von Huene found NHMUK R3078 and the 'C. leedsi'
type specimen to be too different from 'Cetiosaurus', warranting its
own genus, which he named 'Cetiosauriscus', meaning
"'Cetiosaurus'-like". 'Cetiosauriscus leedsi' was referred to the
sauropod family Diplodocidae because of similarities in the tail and
foot, and had the dubious or indeterminate species "Cetiosauriscus"
'greppini', "C." 'longus', and "C." 'glymptonensis' assigned to it. In
1980, Alan Charig named a new species of 'Cetiosauriscus' for NHMUK
R3078 because of the lack of comparable material to the type of 'C.
leedsi'; this species was named 'Cetiosauriscus stewarti'. Because of
the poor state of preservation of the 'Cetiosauriscus leedsi' fossil,
Charig sent a petition to the International Commission on Zoological
Nomenclature to instead make 'C. stewarti' the type species.
'Cetiosauriscus stewarti' became the oldest confirmed diplodocid until
a phylogenetic analysis published in 2003 instead found the species to
belong to Mamenchisauridae, and followed by studies in 2005 and 2015
that found it outside Neosauropoda, while not a mamenchisaurid proper.
'Cetiosauriscus' was found in the marine deposits of the Oxford Clay
Formation alongside many different invertebrate groups, marine
ichthyosaurs, plesiosaurs and crocodylians, a single pterosaur, and
various dinosaurs: the ankylosaur 'Sarcolestes', the stegosaurs
'Lexovisaurus' and 'Loricatosaurus', the ornithopod 'Callovosaurus',
as well as some unnamed taxa. The theropods 'Eustreptospondylus' and
'Metriacanthosaurus' are known from the formation, although probably
not from the same level as 'Cetiosauriscus'.
Background
============
The fossil later known as 'Cetiosauriscus' was originally ascribed to
the genus 'Cetiosaurus'—one of the first sauropods to be named, in
1842 by palaeontologist Richard Owen, and one with a complicated
history due to many unfounded referrals of species and specimens,
involving almost all English sauropod specimens. The type species of
'Cetiosaurus' has changed throughout history because of incomplete
remains and the taxon's significance, and many aspects of its anatomy
and relationships are still uncertain. 'Cetiosaurus' was originally
named to include 'C. medius', 'C. brevis', 'C. brachyurus' and 'C.
longus', which span from the Middle Jurassic to the Early Cretaceous
of various localities across England. As none of these species are
truly diagnostic, and 'Cetiosaurus' is a historically and
taxonomically important taxon, the more complete Middle Jurassic
species 'C. oxoniensis' named by geologist John Phillips in 1871
became the type species. 'C. glymptonensis' was also named in the same
publication by Phillips, but is less complete and of questionable
validity.
Another English taxon, 'Ornithopsis hulkei', was named in 1870 by
palaeontologist Harry Govier Seeley for vertebrae from the Early
Cretaceous Wessex Formation, younger than the existing species of
'Cetiosaurus'. Seeley considered 'Ornithopsis' to be closely related
to 'Cetiosaurus', but different due to the internal bone structure. An
additional species, 'Ornithopsis leedsii' was named in 1887 by John
Hulke for a pelvis, vertebrae and ribs collected by Alfred Nicholson
Leeds, an English farmer and amateur fossil collector who throughout
his life compiled numerous collections of fossils from the Oxford
Clay. 'O. leedsii', from the Late Jurassic, showed similarities to
older 'Cetiosaurus oxoniensis' as well as younger 'O. hulkei'. It was
described in more detail by Seeley in 1889, where he considered 'O.
hulkei', 'C. oxoniensis' and 'O. leedsii' to all be in the same genus,
bearing the name 'Cetiosaurus'. But naturalist Richard Lydekker
discussed with Seeley, before the publication of Seeley's 1889 paper,
that 'Cetiosaurus' and 'Ornithopsis' were not the same taxon. Lydekker
suggested that Wealden fossils (including 'O. hulkei') belonged to
'Ornithopsis' and the Jurassic remains (including 'O. leedsii' and 'C.
oxoniensis') to 'Cetiosaurus'. Lydekker in 1895 changed his mind and
referred the species 'O. leedsii' to 'Pelorosaurus' (known already
from the species 'P. brevis', once named 'Cetiosaurus brevis')—as 'P.
leedsi'—and referred the genus to Atlantosauridae. Lydekker's
classification of the species was not supported by later authors like
palaeontologist Arthur Smith Woodward in 1905, who followed Seeley's
classification scheme.
Discovery and naming
======================
The sauropod fossil today known as 'Cetiosauriscus stewarti' was
discovered in May 1898 by clay workers in the area around Fletton to
the south of Peterborough and east of the Great Northern Railway line.
Pits in this region expose the fossil-rich sedimentary rocks of the
marine Oxford Clay, which is of middle Callovian age and today
regarded as one of the classic geological formations of British
palaeontology. The sauropod fossil possibly stems from NPBCL pit No.1,
which was the northernmost pit operated by the New Peterborough Brick
Company Limited, and which produced the most vertebrate fossils. The
discovery was brought to the attention of Leeds, who, after
excavation, took the sauropod specimen to Eyebury, the Leeds' family
home. In mid-August, after some cleaning and repairing of the
specimen, geologist Henry Woodward visited Eyebury and produced a
life-sized drawing of the remains for presentation at the British
Association for the Advancement of Science Meeting. Following this
presentation, on 17 August 1898, Henry Woodward returned with American
palaeontologist Othniel Charles Marsh, who considered the sauropod to
be closely related to the North American taxon 'Diplodocus'. Alfred
Leeds offered the sauropod to the British Museum of Natural History
(BMNH, now abbreviated as NHMUK) for £250, which would equate to about
£30,529 in 2017. The NHMUK had earlier in 1890 and 1892 bought the
First and Second Collections of Alfred Leeds, respectively. Woodward,
Keeper of Geology at the NHMUK, had "great pleasure" to recommend to
the Trustees of the NHMUK the fossil be purchased. The purchase was
sanctioned on 25 February 1899, along with the purchase of assorted
other remains for just over £357 (~£43,596 now), where the Leeds
sauropod gained the accession number BMNH R3078 (now NHMUK R3078).
The amount of material made NHMUK R3078 the most complete sauropod
specimen from the United Kingdom, comparable only later to the
"Rutland Dinosaur" (referred to 'Cetiosaurus') discovered in 1967.
Known regions of the specimen include the forelimb, hindlimb and
vertebral column. The forelimb lacks the manus (hand) and part of the
radius and ulna, although the hindlimb lacks only a few bones in the
pes (foot) and fragments of the tibia, fibula and ilium. The vertebrae
known are four parts of dorsal vertebrae, the neural spines of the
sacrum, multiple anterior caudal vertebrae (tail bones), and a series
of 27 nearly complete vertebrae from the middle of the tail with
associated or articulated chevrons (ribs along the underside of the
tail), although the vertebral series is not continuous. A tail tip
(NHMUK R1967) from the same locality, but a different individual was
thought by palaeontologist Alan Charig in 1980 to belong to
'Cetiosauriscus'. The assignment of NHMUK R1967 to 'Cetiosauriscus'
was considered unlikely in alternate studies by palaeontologists
Friedrich von Huene, Paul Upchurch and Darren Naish because of the
lack of overlap and uncertain phylogenetic positions. In 1903, the
skeleton was mounted as preserved in the British Museum, so it could
be more easily compared with other mounted sauropods from North
America. The mount of 'Cetiosauriscus' was put on display just prior
to the cast skeleton of 'Diplodocus', and was displayed with the
dorsal vertebrae NHMUK R1984 and some isolated teeth from a
camarasaurid (possibly referable to 'Cetiosauriscus'), making it the
first sauropod skeleton mounted in the United Kingdom.
NHMUK R3078 was referred in 1905 by Arthur Woodward to the species
'Cetiosaurus leedsi', as it was from the same geologic formation as
other specimens that were assigned to 'C. leedsii'. Woodward also
referred the dorsal vertebrae NHMUK R1984 and the tail tip NHMUK R1967
to the species. In 1927, Huene briefly described the anatomy of the
species 'C. leedsii', where he noted that it shared many similarities
with 'Haplocanthosaurus' and was most likely between 'Cetiosaurus'
proper and the former genus. For this reason, Huene proposed the new
genus name 'Cetiosauriscus' for the species. To the genus he referred
the specimens NHMUK R1984-R1988 and NHMUK R3078.
Misassigned species
=====================
Huene (1927) assigned '"Ornithopsis" greppini', which he had named in
1922, to the genus 'Cetiosauriscus'. The known material, discovered in
Late Jurassic (Kimmeridgian) deposits in the Reuchenette Formation of
Switzerland, includes dorsal and caudal vertebrae, forelimb bones, and
a hindlimb and partial pes, from at least two individuals. The 53 cm
long humerus was built like 'Cetiosauriscus stewarti' ('C. leedsi' of
von Huene's 1927 usage), and the two species were originally
distinguished from 'Cetiosaurus' by having shorter dorsal vertebrae, a
shorter forelimb, and a longer lower leg. Similarities such as the
anatomy of the caudal vertebrae were suggested by Christian Meyer and
Basil Thüring in 2003 to support the referral of 'greppini' to
'Cetiosauriscus'. However, Weishampel et al. (2004) and Whitlock
(2011) considered '"Cetiosauriscus" greppini' to be Eusauropoda
'incertae sedis', while Hofer (2005) and Schwarz et al. (2007)
concluded that '"Cetiosauriscus" greppini' represents an unnamed genus
of basal eusauropod. '"Ornithopsis" greppini' was finally named as the
new genus 'Amanzia' in 2020.
The species 'Cetiosaurus longus', named in 1842 by Owen, was referred
to the genus 'Cetiosauriscus' without comment by sauropod
palaeontologist John Stanton McIntosh in 1990. The species was named
for a dorsal and caudal vertebrae from the Portland Stone of
Garsington, Oxfordshire (both now missing) and two other caudal
vertebrae from the same deposit of nearby Thame. Owen also referred a
single vertebra and some metatarsals originally named 'Cetiosaurus
epioolithicus' (an invalid 'nomen nudum') to the species. One of the
vertebrae (OUMNH J13871) may instead be a cervical, as it has one
mildly convex and one concave articular face. Characterised as having
uniquely elongate vertebral centra (body of the vertebra), 'C. longus'
is not a diagnostic taxon. As it lacks any diagnostic features of
'Cetiosauriscus', the species should be referred to by its original
designation, 'Cetiosaurus longus'.
'Cetiosaurus glymptonensis', named on the basis of nine middle-distal
caudal centra from the Forest Marble Formation of Oxfordshire,
England, was referred to 'Cetiosauriscus' by McIntosh in 1990. These
caudal vertebrae were considered to be more elongate than those of
'Cetiosaurus oxoniensis', but caudal length proportions vary
significantly throughout the tail and in different taxa,
'Apatosaurus', 'Diplodocus' and 'Cetiosauriscus' having similarly
elongate caudal vertebrae. The more anterior caudals have a large
ridge two-thirds up the centrum and a smaller ridge one-third up.
These ridges are similar to the middle caudals of 'Cetiosauriscus'.
Still, they are absent in caudals of the same size and proportions,
and because of this difference the species was concluded to be
separate from 'Cetiosauriscus' by Upchurch and Martin in 2003.
"Cetiosaurus" 'glymptonensis' is considered to be Eusauropoda
'incertae sedis' by Upchurch and Martin (2003), Weishampel and
colleagues (2004) and Whitlock (2011), and is in need of a new genus
name because it has a single diagnostic feature, the lateral ridges.
In 1980, Charig described a specimen of indeterminate diplodocid from
the Early Cretaceous of England, and re-examined the holotype of
'Cetiosauriscus leedsii' to compare its characteristics. In this
publication he confirmed that the ilium of the holotype of 'C.
leedsi', NHMUK R1988, was too incomplete to be compared to the also
incomplete ilium of the referred specimen NHMUK R3078. Because of the
lack of overlap the referral of NHMUK R3078 to 'Cetiosauriscus
leedsii' was no longer verifiable, so Charig named the new species
'Cetiosauriscus stewarti' for NHMUK R3078. The specific name was
chosen to honour Sir Ronald Stewart, the chairman of the London Brick
Company that owned the clay pit the fossils had been found in.
Furthermore, Charig considered 'Cetiosauriscus leedsii' and
'Cetiosauriscus greppini' to be dubious taxa, making 'C. stewarti' the
only valid species within 'Cetiosauriscus'. Because of the invalidity
of the type species 'C. leedsii', Charig made a petition to the
International Code of Zoological Nomenclature (ICZN) in 1993 to
designate 'Cetiosauriscus stewarti' as the type species of its genus,
being the taxon containing the specimen Huene had originally named the
genus for and distinguished from 'Cetiosaurus', and also a
taxonomically more stable name. This was accepted by the ICZN in 1995,
making 'Cetiosauriscus stewarti' the type species of 'Cetiosauriscus'.
The only specimen that can confidently be assigned to 'C. stewarti' is
the holotype NHMUK R3078, although it is possible that isolated teeth
from the Oxford Clay could be from the taxon.
Description
======================================================================
'Cetiosauriscus' was a moderately sized, quadrupedal eusauropod. It
had a moderately long tail, and relatively long arms making the
shoulders level with the hips. 'Cetiosauriscus' was approximately 15 m
long based on the known skeleton, comparable to possible relatives
like 16 m long 'Cetiosaurus', and 16.5 m long 'Patagosaurus'. The
weight of 'Cetiosauriscus' is less certain, depending on its
phylogenetic placement. Restored as a diplodocid, 'Cetiosauriscus' was
estimated by Paul (2010) as 4 tonne, but restored as a cetiosaur it
was estimated by Paul (2016) as 10 tonne.
Vertebrae
===========
The dorsal vertebrae of NHMUK R3078 are incomplete or fragmentary. A
partial anterior dorsal is known from a single centrum, which is about
as long as wide, with a strong anterior articular ball (an
opisthocoelous condition). On the lateral surfaces (sides) of the
centrum there are deep but small pleurocoels (depressions in the sides
of vertebrae for air sacs). A single middle dorsal centrum is
preserved, slightly smaller than the anterior dorsal. The pleurocoel
is more elongate, but like the anterior dorsal there is no ventral
(underside) concavity. A posterior dorsal is also known and is
probably the last dorsal before the sacrum (vertebrae between the
pelves). It preserves the entire centrum and most of the neural arch,
and is significantly shortened in length compared to the other
dorsals, although it is about as wide across as tall. A shallow
pleurocoel is also present, but is placed higher on the side of the
centrum and disappears into the neural arch. Unlike the anterior
dorsal, the posterior dorsal is only very slightly opisthocoelous. A
tall and narrow hyposphene (thin vertical ridge below the anterior
processes of the arch, providing additional vertebral articulation) is
present and well expanded off the arch. A single dorsal neural spine
is also preserved. It is flattened and not tall, with a narrowed tip,
and the only noticeable laminae present are the spinopostzygapophyseal
laminae running down the rear corners of the spine to the
postzygapophyses. This is unlike most diplodocoids where there are
many laminar running along the length of the spines. Four neural
spines of the sacrum are preserved, three of which form a single plate
and the fourth of which is separate, like in 'Diplodocus'.
Of the anterior four caudal vertebrae, the anteriormost two are highly
incomplete. Both the short, but wider-than-tall, centra preserve
traces of the sideways projections (transverse processes) found in
other vertebrae, which are very low on the sides compared to following
caudals. The neural spines are very thin, thinning to a single ridge
in front (the prespinal lamina), but having two spinopostzygapophyseal
laminae like the dorsals. The fourth caudal is the most complete
anterior caudal. The centrum is concave in front, but flat behind
(amphiplatyan). There are no pleurocoels unlike the dorsals, and the
transverse processes begin in the top half of the centrum. The centrum
is 10 cm long, 27 cm tall and 28 cm wide, with the total vertebra
being 66 cm tall. Anterior caudals of the 'Cetiosaurus leedsi'
specimen NHMUK R1984 are very similar to those of 'Cetiosauriscus',
but the neural arches are not as tall in 'C. leedsi', and the
transverse processes lack a prominent ridge along the top of them.
Middle and posterior caudals from a nearly continuous series of 27
bones are well preserved in 'Cetiosauriscus'. The later vertebrae are
slightly more elongate than those in front, and slightly less concave
in their anterior face. Moving towards the end of the tail the centra
reduce in size and the transverse processes shrink until they are
completely absent, with the neural spines becoming shorter, thinner,
and more slanted. The seventh vertebrae of the series, at 45 cm tall,
is 18 cm long, only one cm longer than the 21st of the same series
that is 22.5 cm tall. A distinguishing characteristic of
'Cetiosauriscus' is the presence of a front-to-back concavity on the
top of the anterior and middle caudal neural spines.
Appendicular skeleton
=======================
'Cetiosauriscus' preserves a single right scapula (shoulder blade),
which is elongate and slender. The scapula is 96.5 cm long and 17.5 cm
wide at the middle, making it very narrow. The inner face is flat
across, while the outer face is gently convex. There is no expansion
of the far end of the blade. The bone thickens close to the humerus
joint, where it also articulates with the coracoid. The coracoid is
incomplete, but enough is preserved to show it is rectangular, and
longer, at 35 cm, than it is wide—38 cm. A 94 cm long humerus is
known, and complete with minimal crushing. The bone is short and
stout, with a robust crest for the deltoid muscle along the upper half
of the bone. The shape of the humerus is similar to the shortness of
'Neuquensaurus', although overall the forelimb is long, as in
'Diplodocus' and 'Cetiosaurus', being 69% of the femur length. The
distal end is roughened for a large cartilage cap as found in some
other eusauropods like "Cetiosauriscus" 'greppini'. The radius and
ulna are broken, but complete they would have been 76 cm long.
The hindlimb of 'Cetiosauriscus' is about the length of the forelimb.
Both ilia are very fragmentary, but the two sides supplement each
other to give a reasonable idea of the proportions of the complete
bone. The ilium is 1.02 m long, and has a long and slender pubic
peduncle. It is proportionally lower than in 'Cetiosaurus', being
similar in proportions to 'Haplocanthosaurus' and the later
"Titanosauridae". The left femur is complete, but part of the shaft is
eroded away. It is very slender, being 1.36 m tall but only 19.5 cm
wide at the middle. This very gracile femoral morphology is shared
with 'Amphicoelias', 'Shunosaurus', 'Ligabuesaurus' and a specimen of
'Diplodocus', being more gracile than 'Cetiosaurus' and most other
eusauropods. A prominent fourth trochanter is present, but the
remaining shaft is very compressed. The tibia, fibula and pes are also
preserved, but are fragmentary and disarticulated making comparisons
difficult, the lower hindlimb being about 80 cm upright. The foot is
similar to 'Diplodocus' and 'Brontosaurus', where the first toes are
large and clawed, and the outer ones are small and clawless.
Metatarsal III is the longest, followed by metatarsal IV, II, V and I.
Metatarsal I is the widest, and the width of the bones decreases
numerically.
Classification
======================================================================
'Cetiosauriscus' was originally classified by Huene as a genus in the
family Cetiosauridae, within the subfamily Cardiodontidae. The
subfamily, including the other taxa 'Cetiosaurus',
'Haplocanthosaurus', 'Dystrophaeus', 'Elosaurus' and 'Rhoetosaurus',
was founded upon the general basal features of elongate cervicals and
shortened dorsals—both opisthocoelous, amphicoelous caudals that are
rod-shaped distally, paired sternal plates, an ilium lacking the
postacetabular process (region of the ilium behind the ischium joint
and acetabulum), a very wide pubis, wide distal ischium, significantly
shorter forelimb than hindlimb, fibula lacking the middle muscle
attachment, and long metacarpals and short metatarsals. This
classification was emmended in 1932 when Huene concluded
'Cetiosauriscus' was closer to 'Haplocanthosaurus' than 'Cetiosaurus'
in the family, because of forelimb and hindlimb proportions.
Conversely, in 1956, Alfred Romer synonymised 'Cetiosauriscus' and
'Cetiosaurus', a position that has not been followed by subsequent
studies on the taxon.
David S. Berman and McIntosh in 1978 referred 'Cetiosauriscus' to the
family Diplodocidae along with multiple other genera; 'Diplodocus',
'Apatosaurus', 'Barosaurus', 'Mamenchisaurus' 'Dicraeosaurus' and
'Nemegtosaurus'. Like other members of the family, 'Cetiosauriscus'
possesses wing-like transverse processes, divided chevrons with
forward and backward projections, the tail is "whiplash"-like, the
humerus is 2/3 the length of the femur, the calcaneum is absent,
metatarsal III and IV are the longest, and metatarsal I has a process
on the bottom back corner. This referral would make 'Cetiosauriscus',
known from the Callovian, the oldest diplodocid, millions of years
older than 'Diplodocus', 'Barosaurus' or 'Apatosaurus'. In the paper
naming 'Cetiosauriscus stewarti', Charig also described the chevrons
of a new specimen and created the term "diplodociform" to describe
them. This meant they were robust and double-beamed, as in
'Diplodocus' and its relatives like 'Mamenchisaurus'. Because of the
similarly "diplodociform" chevrons, Charig referred 'Cetiosauriscus'
to the Diplodocidae along with the new specimen. Elaborating upon his
earlier paper, McIntosh (1990) weakly referred 'Cetiosauriscus' to the
subfamily Diplodocinae, characterised by more cervicals and fewer
dorsals, tall sacrum neural spines, short forelimbs, no calcaneum,
metatarsals III and IV being the longest, and a small process on the
distal end of metatarsal I. The subfamily also included 'Diplodocus',
'Barosaurus' and 'Apatosaurus'. In 2004 this placement was followed by
Weishampel 'et al.' without comment.
A phylogenetic analysis of 'Cetiosauriscus' was conducted in 2003 by
Julia Heathcote and Upchurch, based upon the two most inclusive
matrices of the time, those of Jeffrey A. Wilson (2002) and Upchurch
(1995), neither of which had included the taxon in the past. Added to
the analysis of Upchurch, 'Cetiosauriscus' placed as the sister taxon
of 'Tehuelchesaurus', in a group including 'Mamenchisaurus',
'Omeisaurus' and 'Euhelopus', and a placement within a group of
'Omeisaurus' and 'Mamenchisaurus' was also found by using the Wilson
matrix. Based on these two results, Heathcote and Upchurch concluded
'Cetiosauriscus' was not a diplodocid or even within Diplodocoidea,
instead being a more basal sauropod outside Neosauropoda. The
phylogenetic analysis of Rauhut 'et al.' (2005) resolved
'Cetiosauriscus' in a clade with 'Omeisaurus', itself in a group with
'Losillasaurus' and 'Mamenchisaurus', outside of Neosauropoda. The
phylogenetic relationships of 'Cetiosauriscus' were also tested in
2015 by Tschopp 'et al.', as a potential diplodocid. Although the
genus was found to be within Diplodocimorpha with one analysis method,
it was also found outside Neosauropoda. In both, 'Cetiosauriscus
stewarti' was found to be in a clade alone with 'Barosaurus affinis',
a dubious species known only from foot bones. Tschopp 'et al.'
concluded that 'Cetiosauriscus' was not a diplodocid or a diplodocoid,
as forcing it to be outside Neosauropoda was more parsimonious than
forcing it to be within Diplodocoidea in all analyses. As the paper
was only to test relationships within Diplodocidae, more solid
conclusions regarding the position of 'Cetiosauriscus' could not be
made. The results of the favoured cladogram of Tschopp 'et al.' is
shown below:
{{clade| style=font-size: 85%; line-height: 85%;
|label1=Eusauropoda
|1={{clade
|1='Shunosaurus lii'
|2={{clade
|1='Spinophorosaurus nigerensis'
|2={{clade
|1='Omeisaurus'
|2={{clade
|1='Mamenchisaurus'
|2={{clade
|1=
|2={{clade
|1='Jobaria tiguidensis'
|2={{clade
|1={{clade
|1='Amphicoelias latus'
|2={{clade
|1='Lourinhasaurus alenquerensis'
|2= }} }}
|2={{clade
|1='Brachiosaurus' sp.
|2={{clade
|1=Diplodocoidea
|label2=Macronaria
|2= }} }} }} }} }} }} }} }} }} }}
Palaeopathology
=================
The series of distal caudal vertebrae NHMUK R1967, once referred to
'Cetiosauriscus', is similar to the caudals of 'Diplodocus', with two
convex ends (biconvex) and a long and thin centrum. These caudals
display signs of injury at two points along the series of ten
vertebrae, where there are signs of breakage that was later healed.
These lesions were identified as the same form of pathologies as found
on the tail of 'Diplodocus'. It has been suggested that the biconvex
distal caudal vertebrae in sauropods were used for making whip-like
cracking noise, being thin and delicate and not intended for impact,
as the joints would be very vulnerable to damage rendering them
useless.
Palaeoecology
===============
'Cetiosauriscus' lived during the Callovian, an epoch in the Middle
Jurassic, about 166 to 164 mya.
The single specimen is known from the Lower Member of the Oxford Clay
Formation, along with multiple other dinosaur genera and many other
groups of animals, in the biozone of the index fossil 'Kosmoceras
jason'. The Oxford Clay Formation is a marine deposit of southern and
middle England, known for the high-quality preservation of some
fossils and the large diversity of taxa. Sediments are generally
brownish-grey mudstone, organic-rich with plentiful crushed ammonites
and bivalves, at most 65 m thick. A large diversity of flora can be
seen, preserved in the form of pollen and spores. Gymnosperms are
present, along with pteridophytes, unidentifiable wood fragments,
other intermediate pollen, and miscellaneous organic plant material.
The intermediate sauropod 'Ornithopsis leedsi' is known from the same
section of the formation as 'Cetiosauriscus', along with the
stegosaurids 'Lexovisaurus durobrivensis' and 'Loricatosaurus priscus'
(which are possibly synonyms), the basal ankylosaur 'Sarcolestes
leedsi', the ornithopod 'Callovosaurus leedsi', and a second unnamed
ornithopod taxon. Dinosaur eggs that have not yet been assigned to a
taxon are also known from the Lower Oxford Clay. The theropods
'Eustreptospondylus' and possibly 'Megalosaurus' are also known from
the Oxford Clay Formation, but slightly younger deposits (the Middle
Member). In addition, the theropod 'Metriacanthosaurus' is from an
unknown level and age in the formation.
Hundreds of invertebrates are known from the marine deposits,
including bivalves, gastropods, scaphopods, ammonites, teuthoids, a
nautiloid, foraminifera, coelenterates, bryozoans, brachiopods,
annelids, crustaceans, ostracods, cirripedes and echinoderms. Fish are
known from the clades Elasmobranchii, Chimaera, and Actinopterygii,
and the ichthyosaur 'Ophthalmosaurus', the plesiosaurs 'Cryptoclidus',
'Muraenosaurus', 'Tricleidus', 'Liopleurodon', 'Peloneustes',
'Pliosaurus' and 'Simolestes', the crocodilians 'Metriorhynchus' and
'Steneosaurus', and the pterosaur 'Rhamphorhynchus' were all present.
License
=========
All content on Gopherpedia comes from Wikipedia, and is licensed under CC-BY-SA
License URL: http://creativecommons.org/licenses/by-sa/3.0/
Original Article: http://en.wikipedia.org/wiki/Cetiosauriscus
.