View source for Biology:Lohuecotitan

{{Short description|Extinct genus of dinosaurs}} 
{{Italic title}}
{{Speciesbox
| name = ''Lohuecotitan''
| fossil_range = {{fossil range|72}} Upper [[Earth:Campanian|Campanian]]- Lower [[Earth:Maastrichtian|Maastrichtian]] ([[Earth:Late Cretaceous|Late Cretaceous]])
| image =
| genus = Lohuecotitan
| parent_authority = Díez Díaz ''et al''., 2016
| species = pandafilandi
| authority = Díez Díaz ''et al''., 2016
}}

'''''Lohuecotitan''''' is an extinct [[Biology:Genus|genus]] of [[Biology:Titanosaur|titanosaur]]ian sauropod [[Biology:Dinosaur|dinosaur]] which lived during the [[Earth:Late Cretaceous|Late Cretaceous]] in {{wipe|Spain}}. The only species known in the genus is '''''Lohuecotitan pandafilandi''''', described and named in 2016.<ref name=Diaz2016>{{cite journal | language = en | first1 = V. | last1 = Díez Díaz | first2 = P. | last2 = Mocho | first3 = A. | last3 = Páramo | first4 =  F. | last4 = Escaso | first5 = F. | last5 = Marcos-Fernández | first6 =  J.L. | last6 = Sanz | first7 = F. | last7 = Ortega | year = 2016 | title = A new titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Lo Hueco (Cuenca, Spain) | journal = Cretaceous Research | doi = 10.1016/j.cretres.2016.08.001 | volume = 68 | pages = 49–60| bibcode = 2016CrRes..68...49D }}.</ref>

==Discovery and naming==
[[File:Lohueco.jpg|upright|thumb|left|The fossil site of Lo Hueco in 2007, where remains of ''Lohuecotitan'' have been found.]]
The fossil remains of ''Lohuecotitan'' were discovered in the site of Lo Hueco, Fuentes, Cuenca, which is part of the [[Earth:Villalba de la Sierra Formation|Villalba de la Sierra Formation]].<ref name=Diaz2016/> The formation dates from the Upper [[Earth:Campanian|Campanian]] to the Lower [[Earth:Maastrichtian|Maastrichtian]], and would have represented a muddy coastal floodplain.<ref name="Ortegaetal2015">{{cite journal | first1 = F. | last1 = Ortega | first2 = N. | last2 = Bardet | first3 = F. | last3 = Barroso-Barcenilla | first4= P.M. | last4 = Callapez | first5 = O. | last5= Cambra-Moo | first6 = V. | last6 = Daviero- Gómez | first7 = V. | last7 = Díez Díaz | first8 = L. | last8 = Domingo | first9 = A. | last9 = Elvira | first10 = F. | last10 = Escaso | first11 = M. | last11 = García-Oliva | first12 = B. | last12 = Gómez | first13 = A. | last13 = Houssaye | first14 = F. | last14 = Knoll | first15 = F. | last15 = Marcos-Fernández | first16 = M. | last16 = Martín | first17 = P. | last17 = Mocho | first18 =  I. | last18 = Narváez | first19 = A. | last19 = Pérez- García | first20 = D. | last20 = Peyrot | first21 = M. | last21 = Segura | first22 = H. | last22 = Serrano | first23 = A. | last23 = Torices | first24 = D. | last24 = Vidal | first25 = J.L. | last25 = Sanz | title = The biota of the Upper Cretaceous site of "Lo Hueco" (Cuenca, Spain) | journal =  Journal of Iberian Geology| volume = 41 | issue = 1 | date = 2015 | url = http://revistas.ucm.es/index.php/JIGE/article/view/48657 | doi = 10.5209/rev_JIGE.2015.v41.n1.48657| doi-access = free | hdl = 10486/675918 | hdl-access = free }}</ref> The locality was discovered in 2007 during the cutting of a little hill for installation of the railway of the Madrid-Valencia high-speed train. More than 10 000 fossils have been collected, almost half of which belong to titanosaurs comprising more than twenty sets of partial skeletons in anatomical connection or with a low dispersion of their skeletal elements.<ref name="Ortegaetal2015"/> Teeth and braincases were also recovered. The material belongs to at least two distinct types of titanosaur.<ref name="Ortegaetal2015"/><ref name="Knoll2015">{{cite journal | title = A New Titanosaurian Braincase from the Cretaceous "Lo Hueco" Locality in Spain Sheds Light on Neuroanatomical Evolution within Titanosauria | date = 2015 | journal = PLOS ONE | volume = 10 | issue = 10 | pages = e0138233 | doi = 10.1371/journal.pone.0138233 | last1 = Knoll | first1 = F. | last2 = Witmer | first2 = L.M. | last3 = Ridgely | first3 = R.C. | last4 = Ortega | first4 = F. | last5 = Sanz | first5 = J.L. | pmid=26444700 | pmc=4596832| bibcode = 2015PLoSO..1038233K | doi-access = free }}</ref> The holotype specimen of ''Lohuecotitan'', '''HUE-EC-01''', is a disarticulated partial skeleton consisting of cervical, dorsal, sacral, and caudal vertebrae, ribs, an ulna, both ischia, a pubis, a femur, a fibula, and a tibia, along with some indeterminate remains.<ref name=Diaz2016/>

The name of ''Lohuecotitan'' combines a reference to the type locality with ''titan'' (which refers to the Greek titans). The specific name, ''pandafilandi'', is derived from the name of a giant, ''Pandafilando de la fosca vista'', in the novel ''Don Quixote''.<ref name=Diaz2016/>
The character is named "Pandafilando of the Scowl" in John Ormsby's translation.

==Description==
[[File:Lohuecotitan model - Castilla-La Mancha Paleontological Museum 03.jpg|thumb|right|Statue of adult ''Lohuecotitan'' and juvenile outside the Castilla-La Mancha Paleontological Museum]]
''Lohuecotitan'' was recognized by its describers as having a number of unique characteristics ([[Biology:Autapomorphy|autapomorphies]]) not seen in other titanosaurs. In the dorsal vertebrae, the edges of the postspinal [[Biology:Vertebra#Structure|laminae]] extend outwards. In the first several caudal vertebrae, the medial spinoprezygapophyseal and spinopostzygapophyseal laminae respectively connect to the prespinal and postspinal laminae on the bottom surface. In addition, due to the way that the prespinal and postspinal laminae project upwards, the neural spine of the vertebra appears to be V-shaped from the side, and resemble a Greek cross in cross-section. Each middle caudal vertebra has two roughened structures that extend from the top of the back face onto the top surface of the vertebra. Finally, the bottom portion of each half of the haemal arches in the posterior caudal vertebrae is split fully into two articular facets. These traits form a unique combination not seen in other titanosaurs, along with the centrodiapophyseal laminae being widened on the top and bottom edges in the front and middle dorsal vertebrae (as also seen in ''[[Biology:Saltasaurus|Saltasaurus]]''), and a rounded protrusion being present between the front and side trochanters of the fibula (also seen in ''[[Biology:Jainosaurus|Jainosaurus]]'').<ref name=Diaz2016/>

A number of the bones of ''Lohuecotitan'' were internally pneumatized, including the cervical vertebrae, sacral vertebrae, and ilium. As is common in [[Biology:Somphospondyli|somphospondylans]], the pneumatic fossae on the cervical vertebrae are shallow; this was also the case in the dorsal vertebrae. The cervical and dorsal vertebrae are [[Biology:Vertebral column#Variations in vertebrae|opisthocoelous]]; the caudal vertebrae were [[Biology:Vertebral column#Variations in vertebrae|procoelous]] (a characteristic common in [[Biology:Lithostrotia|Lithostrotia]]). The seventh and eighth tail vertebrae are fused together; this probably represents a [[Biology:Pathology|pathology]]. As in other titanosauriforms, the dorsal ribs are compressed and blade-like. The ulna was robust, and the bottom surface of the tibia was oval-shaped, as is common in titanosaurs.<ref name=Diaz2016/>

===Braincase===
[[File:Ampelosaurus braincase.png|thumb|left|300px|Braincase first attributed to ''Ampelosaurus'' sp. then to ''Lohuecotitan'', and CT scans]] 
In 2013 Knoll and colleagues tentatively assigned to an unnamed species of ''[[Biology:Ampelosaurus|Ampelosaurus]]'', ''A.'' sp., a fossil braincase from Lo Hueco.<ref name="Knoll&al2013">{{cite journal |last1=Knoll |first1=F. |author2=Ridgely, R.C. |author3=Ortega, F. |author4=Sanz, J.L. |author5=Witmer, L.M. |year=2013 |title=Neurocranial osteology and neuroanatomy of a Late Cretaceous titanosaurian sauropod from Spain (''Ampelosaurus'' sp.) |journal=PLOS ONE |volume=8 |issue=1 |page=e54991 |doi=10.1371/journal.pone.0054991 |pmid=23355905 |pmc=3552955 |bibcode=2013PLoSO...854991K |doi-access=free }}</ref> However, in 2019 Knoll et al. finally referred this braincase to ''Lohuecotitan''.<ref name="Knoll&al2019">{{cite journal |last1=Knoll |first1=F. |author2=Lautenschlager, S. |author3=Valentin, X. |author4=Díez Díaz, V. |author5=Pereda Suberbiola, X. |author6= Garcia, G. |year=2019 |title=First palaeoneurological study of a sauropod dinosaur from France and its phylogenetic significance |journal=PeerJ |volume=7 |issue= |page=e7991 |doi=10.7717/peerj.7991 |pmid=31763068 |pmc=6871212 |doi-access=free }}</ref> This assignment is based on the fact that another braincase morphotype from Lo Hueco was found to be associated with a titanosaur skeleton distinct from ''Lohuecotitan'' and because none of the very abundant titanosaur postcranial remains of Lo Hueco belong to ''Ampelosaurus''.<ref name="Knoll&al2019"/><ref name=Diaz2016/><ref name="Mocho&al2023">{{cite journal |last1=Mocho |first1=P. |author2=Escaso, F. |author3=Marcos-Fernández, F. |author4=Páramo, A. |author5=Vidal, D. |author6=Ortega, F. |year=2023 |title=Exploring the presence of new titanosaurian taxa in the Campanian-Maastrichtian of the Iberian Peninsula |journal=Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June – 1st July 2023. Palaeovertebrata, Special Volume |volume=1-23 |page=173|url=https://eavp2023.icp.cat/abstract-book-field-trip-guides }}</ref>
The braincase was found to share many features with ''A. atacis'', such as a back of the skull that is flat. The braincase, MCCM-HUE-8741, is small in size overall, with a front-to-back length of {{convert|100.8|mm|in}}, and the maximum width of the left half being {{convert|64.3|mm|in}}. Parts of the bottom half of the braincase are missing. Even though section are missing, the specimen does not appear to have been deformed much, as the left and right halves are not very different.<ref name="knoll2013"/>
 
Two frontals are preserved. They are each {{convert|57.3|mm|in}} long and {{convert|64.3|mm|in}} wide. The upper surface of each frontal is not smooth. One crest runs along the each frontal, and the together the two crests make up the [[Physics:Orbit|orbital roof]]. Both [[Biology:Parietal bone|parietal]]s have also been found. The connection between them is marked by a ω-shaped crest. Viewed from the side, the parietal has two extensions. These extensions are not fully preserved, but they would have been on the border of the [[Biology:Skull#Temporal fenestrae|upper temporal fenestrae]] in their middle. Each parietal was preserved as {{convert|79.6|mm|in}} wide. The [[Biology:Skull|basioccipital]] of ''Lohuecotitan'' is unique as it has an occipital condyle that is much wider than tall. The occipital condyle has an irregular surface that was probably caused by the loss of the original [[Biology:Cartilage|cartilaginous covering]]. The complete braincase was especially low in the skull, and was oriented to the side. The occipital condyle is {{convert|28.6|mm|in}} wide and {{convert|15.8|mm|in}} tall.<ref name="knoll2013"/> The braincase floor is made by the [[Biology:Skull|parabasisphenoid]]. The [[Biology:Skull#prootic|prootic]] is a tall but not long bone. The basisphenoid is mostly on the side of it, along with the [[Biology:Skull#laterosphenoid|laterosphenoid]], the parietal, and the otoccipital. The length of the prootic from the front to the back is around {{convert|10.6|mm|in}}.<ref name="knoll2013"/> 

====Neuroanatomy====
[[File:Ampelosaurus endocast.png|thumb|Endocast of the brain showing the labyrinth]]
Compared with ''Giraffititan'', the inner ear of ''Lohuecotitan'' shows a more basal morphology. That feature is possibly related to a restricted range of possible movements that involve head-turning.<ref name="knoll2013">{{Cite journal | last1 = Knoll | first1 = F. | last2 = Ridgely | first2 = R. C. | last3 = Ortega | first3 = F. | last4 = Sanz | first4 = J. L. | last5 = Witmer | first5 = L. M. | editor1-last = Butler | editor1-first = Richard J | title = Neurocranial Osteology and Neuroanatomy of a Late Cretaceous Titanosaurian Sauropod from Spain (Ampelosaurus sp.) | doi = 10.1371/journal.pone.0054991 | journal = PLOS ONE | volume = 8 | issue = 1 | pages = e54991 | year = 2013 | pmid =  23355905| pmc = 3552955| bibcode = 2013PLoSO...854991K | doi-access = free }}</ref>

Like in ''[[Biology:Jainosaurus|Jainosaurus]]'' and most other non-avian archosaurs, the hindbrain and midbrain of ''Lohuecotitan'' is relatively poorly preserved in the [[Biology:Endocast|endocast]]. In contrast with TMM 40435 and a few other taxa such as ''cf. Cetiosaurus oxoniensis'' and ''Giraffatitan'', no characteristic "nub" of the [[Biology:Cerebellum|cerebellum]] can be seen. As in TMM 40435 and many other archosaurs, the back of the [[Biology:Brain|brain]] is especially narrow in ''Lohuecotitan''.<ref name="knoll2013"/>

The [[Biology:Brain#Cerebral region|cerebral region]] of the brain is separated from the rest of the brain by a distinct compression caused in the endocranial cavity. The rearmost part of the cerebral region of the braincase has a top with a small expansion. This is different from ''Jainosaurus''. However, relatively much larger expansions are known in the diplodocoid sauropods ''Dicraeosaurus'' and ''[[Biology:Diplodocus|Diplodocus]]''. In MCCM-HUE-8741, the small opening in the skull roof middle is responsible for a swelling on the endocast that is suggestive of a [[Biology:Brain#Pineal|pineal system]]. It is in the exact position where the [[Biology:Pineal gland|pineal gland]] is expected to have been, between the [[Biology:Forebrain|forebrain]] and the [[Biology:Midbrain|midbrain]].<ref name="knoll2013"/>

The semicircular canals are contracted, and they are highly curved. The semicircular system of MCCM-HUE-8741 shows also a [[Biology:Basal (phylogenetics)|basal]] morphology, because the semicircular canals do not attach to each other.<ref name="knoll2013"/>

==Classification==
''Lohuecotitan'' was in 2016 recovered as a [[Biology:Lithostrotia|lithostrotia]]n [[Biology:Titanosaur|titanosaur]], more derived than ''[[Biology:Malawisaurus|Malawisaurus]]''. Its position among the lithostrotians is supported by the sharp angle of its zygapophyseal articulations. The consensus of the 20 most parsimonious phylogenetic trees recovered is shown below.<ref name=Diaz2016/>

{{clade| style=font-size:90%;line-height:90%
|label1=&nbsp;[[Biology:Lithostrotia|Lithostrotia]]&nbsp;
|1={{clade
     |1=''[[Biology:Malawisaurus|Malawisaurus dixleyi]]''
     |2={{clade
          |label6=&nbsp;[[Biology:Saltasaurinae|Saltasaurinae]]&nbsp;
          |1=''[[Biology:Trigonosaurus|Trigonosaurus pricei]]''
          |2='''''Lohuecotitan pandafilandi'''''
          |3=''[[Biology:Alamosaurus|Alamosaurus sanjuanensis]]''
          |4=''[[Biology:Opisthocoelicaudia|Opisthocoelicaudia skarzynskii]]''
          |5=''[[Biology:Nemegtosaurus|Nemegtosaurus mongoliensis]]''
          |6={{clade
               |1=''[[Biology:Neuquensaurus|Neuquensaurus australis]]''
               |2=''[[Biology:Saltasaurus|Saltasaurus loricatus]]''}}
          |7={{clade
               |1=''[[Biology:Rapetosaurus|Rapetosaurus krausei]]''
               |2={{clade
                    |1=''[[Biology:Isisaurus|Isisaurus colberti]]''
                    |2=''[[Biology:Tapuiasaurus|Tapuiasaurus macedoi]]''}}}}}}}}}}

==See also==
*2016 in paleontology

==References==
{{Reflist}}
{{Taxonbar|from=Q26261015}}

[[Category:Titanosaurs]]
[[Category:Campanian life]]

{{Sourceattribution|Lohuecotitan}}