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Herbivore dinosaurs...
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I'd like to make a post about the potential size of the sauropod Notocolossus.
In regards to its mass, Greg Paul (2019), on the basis of the size of its dorsal centrum, estimates it to be comparable in size to Patagotitan at 45-55 tonnes, with the possibility that it may be larger and closer to Argentinosaurus in size at 65-75 tonnes. I'm inclined to agree with this because, as stated in the linked paper, the centrum in the only preserved dorsal vertebra is about the same size as that in Patagotitan/Puertasaurus, yet many titanosaurs have shorter anterior dorsals than posterior so the animal may have been larger than Patagotitan and closer to Argentinosaurus; these sizes are also supported by the size of the humerus (176 cm, Gonzalez-Riga, 2016). Length can be inferred based on cross scaling its dorsal vertebrae to more complete relatives; as per Carballido et al. 2017, the width of the diapophysis of the second dorsal vertebra of Patagotitan, Notocolossus, and Puertasaurus are 140, 150, and 168 cm, respectively, and the wider a titanosaur's ribcage is, the wider its diapophyses are in order to support that width. Randomdinos restores Puertasaurus at 28.6 meters and 60 tonnes (note that it may very well be up to 35 meters and 100-110 tonnes as per some other reconstructions, but I'll use this one because it has a mass estimation), and Patagotitan at 30 meters and 55 tonnes (Greg Paul restores both animals at approximately these sizes as well). This means Puertasaurus possesses a diapophysis 20% wider than Patagotitan and is thus 25.9% heavier at the same length. Applying this disparity to the disparity between Patagotitan and Notocolossus dorsal width (150 vs 140 cm) suggests Notocolossus would be slightly over 12.4 percent heavier at length parity (meaning, for example, a 30 meter Notocolossus would be 61.8 tonnes compared to 55 tonnes for a 30 meter Patagotitan). So overall, if we were to use Greg Paul's estimates as the basis for mass, this means that Notocolossus would have been ~27-32 meters long and 45-75 tonnes in weight. Interestingly this is almost exactly the same as the 45-76 tonnes the Notocolossus holotype was estimated to weigh via the circumference of its humerus in Gonzalez-Riga et al. 2016. 
" Therizinosaurus is a genus of very large theropod dinosaurs. Therizinosaurus comprises the single species T. cheloniformis, which lived in the late Cretaceous Period, and was one of the last and largest representatives of its unique group, the Therizinosauria.
Mass: 5,000 kg Lived: 72.1 million years ago - 66 million years ago (Maastrichtian) Scientific name: Therizinosaurus (Scythe lizard) Did you know: The feeding habits of Therizinosaurus are unknown, since no skull material has ever been found that could indicate its diet. "
There is a very large sauropod humerus from Thailand mentioned in an abstract. It's very likely the largest titanosaur humerus we have so far if the measurement is correct.
The abstract is as follows: "THE GIGANTIC TITANOSAURIFORM SAUROPOD FROM THE EARLY CRETACEOUS KHOK KRUAT FORMATION IN THE NORTHEASTERN OF THAILAND: A PRELIMINARY REPORT KHANSUBHA, Sasidhorn, Department of Mineral Resources, Bangkok, Thailand; POTHICHAIYA, Cherdchan, Department of Mineral Resources, Bangkok, Thailand; RUGBUMRUNG, Mana, Department of Mineral Resources, Bangkok, Thailand; MEESOOK, Assanee, Department of Mineral Resources, Bangkok, Thailand Here is a preliminary report on the most recent find of an immense sauropod from the Early Cretaceous Khok Kruat Formation at Ban Pha Nang Sua, Nong Bua Rawe District, Chaiyaphum Province, Northeastern Thailand. In early March 2016, a local villager found an exposed of a sauropod sacrum at the bank of pond in the village. Later, geologists from the Department of Mineral Resources have investigated and started a systematic excavation during April-June 2016, discovered several post-cranial specimen from an individual sauropod comprising an axial skeleton (dorsal vertebra and sacral vertebrae) and an appendicular skeleton (a complete well-preserved right humerus, 1.78 m in length, a large dorsal ribs, a partial small rib, two pieces of partial right femur, pelvic girdle and many bone fragments), found associated with several isolated teeth which belong to Allosaurid and Spinosaurid theropods. Associated faunas include Hybodont shark Heteroptychodus sp. and crocodilian teeth. According to a preparatory study on humeral morphological features suggested that this new find possibly belong to a new taxon of giant titanosauriform sauropod dinosaur from the Khok Kruat Formation of Northeastern Thailand Lithostratigraphically, the sequence of the Khok Kruat Formation at the Pha Nang Sua dinosaur site, can be divided into nine units i.e., Units 1-9, having approximately 3.96 m thick. Dinosaur bones and fragments are found in the lower part of the sequence consisting mainly of reddish brown sandstones and siltstones with conspicuous climbing ripple lamination of Units 1-3. The top of this part consists of a thin layer (Unit 4) of calcrete paleosol. Sandstones from Units 5-9 display various directions of cross bedding and the bones are absent. This may indicate that the dinosaur bones are found in the crevasse splay layers and the channel and channelized sandstone are represented by the sandstones of the upper part of the sequence. The rocks are interpreted as having been deposited by the meandering rivers for Khok Kruat Formation in semi-arid to arid paleoclimate. More details on anatomical and phylogenetic studies and further excavations are essential to complete and compare with other vicinity sauropods. The measured section and faunal assemblage from Ban Pha Nang Sua dinosaur site is not only useful for lithostratigraphic and faunal correlations to other vertebrate sites. This new dinosaur locality will also shade light and figure out more understanding on sauropod evolution, distribution and paleoenvironment in this region." Given that it appears to be classified as a titanosaur and was found very close geographically and temporally to Phuwiangosaurus, it's likely a good idea to use the latter to scale the humerus. As for mass, Greg Paul (2016) estimates Phuwiangosaurus at 17 tonnes, and following Klein and Sander (2009) on its histology, the largest humerus from it is 110 cm long. Isometrically scaling from a 17 tonne Phuwiangosaurus with a 110 cm humerus, this specimen ends up at 72 tonnes. So this is undoubtedly a very large animal as the abstract suggests. Lengthwise, this animal was likely upwards of 30 meters. Paul estimates Phuwiangosaurus at 19 meters, which would lead to a 30.5 meter long animal scaled up isometrically. However, as sauropods grew larger their necks would have grown to the power of 1.35 in respect to torso length (link), so this is likely not long enough. This skeletal from Paleocritti can help us quantify how much this length increase would be. The neck is about one third of the total length, and would thus be about 10.17 meters on a 30.5 meter Phuwiangosaurus-like form. Applying neck allometry (10.17x1.35-10.17) gives us about 3.55 meters of 'extra' length to add onto the extrapolated 30.5 meters. Overall, provided this scaling holds, this appears to be an animal approximately 34 meters long and 72 tonnes in weight.
There is a very large, unnamed sauropod from the Candeleros. SpinoInWonderland has made a good analysis on its size here:
https://thesauropodomorphlair.wordpress.com/2020/06/04/the-candeleros-monster/
I'd like to make a post on the size of an unnamed giant mamenchisaurid fossil reported here: http://www.china.org.cn/english/culture/72851.htm
The diameter of this animal's femur is exactly twice that of Mamenchisaurus youngi (15 cm according to the supplementary material of Benson 2014), and assuming relative geometric similarity it would be twice as big linearly and 8 times more massive. (Greg Paul's estimation for M. youngi in the 2016 Princeton Field Guide to Dinosaurs was 16 meters and 7 tonnes, but his model is somewhat shrinkwrapped and a healthy model is probably closer to 8). So based on the healthy model for Mamenchisaurus youngi at least, this animal would be around 32 meters long and 64 tonnes. Sizes like this are also supported by the length of the hindlimb - while it is incomplete it is 3 meters as preserved, and would be even larger complete. On his website, Greg Paul estimates a Mamenchisaurus hochuanensis with a 135 cm femur to weigh 14 tonnes, and given that femur length, his skeletal yields a hindlimb length of 2 meters (link). Scaling that up to the incomplete hindlimb length alone yields over 47 tonnes, and would be even larger using the full hindlimb to scale (which would be 358 cm based on Mamenchisaurus youngi given a 112.5 cm femur and 66.5 cm tibia for M. youngi as well as the greater diameter). Given that hindlimb length, as well as his length estimation of 20 meters in the 2016 Princeton Field Guide to Dinosaurs, the hindlimb would be about 35.8 meters and 80.3 tonnes scaling from M. hochuanensis. As for what it is, it could be a new species, but given its size and where it was discovered I wouldn't be surprised if it turns out to be a new specimen of Mamenchisaurus sinocanadorum.
" This picture shows a mounted skeleton of Amargasaurus in Victoria Museum, Melbourne, Australia. ?
Amargasaurus ("La Amarga lizard") is a genus of sauropod dinosaur from the Early Cretaceous epoch (129.4–122.46 mya) of what is now Argentina. The only known skeleton was discovered in 1984 and is virtually complete, including a fragmentary skull, making Amargasaurus one of the best-known sauropods of its epoch. Amargasaurus was first described in 1991 and contains a single known species, Amargasaurus cazaui. It was a large animal, but small for a sauropod, reaching 9 to 10 meters (30 to 33 feet) in length. Most distinctively, it sported two parallel rows of tall spines down its neck and back, taller than in any other known sauropod. In life, these spines most likely could have stuck out of the body as solitary structures that supported a keratinous sheath. Length: 9 – 10 m Mass: 2,600 kg Lived: 129.4 million years ago - 122.46 million years ago (Barremian - Aptian) "
Julian Johnson: " Hi heres a therizinosaurus. model can be viewed and downloaded for free here http://skfb.ly/6QQDL "
The fossil bearing content of the Kem Kem beds in North Africa is very famous for the plethora of large dinosaur fossils it produces; among the most famous specimens are giant predatory dinosaurs such as Carcharodontosaurus, Spinosaurus, Bahariasaurus, and Sauroniops. Less well known and much more sparse overall are its sauropods, with relatively few species being found and only 1 medium-large (following Greg Paul, 2019) sauropod (Paralititan) being named thus far.
However, there exist figured yet unnamed titanosaur specimens from the Kem Kem that suggest some of the largest land animals of all time were present in the environment, with the specimens in question being the midshaft of a humerus and the proximal end of an ulna. They may or may not be larger individuals of already known species, and may be either different types of titanosaur or conspecific, but one thing is for certain: both are gigantic. The giant humerus: This humeral shaft may possibly be the largest titanosaur humerus yet discovered. Discovered in 2008 and figured in Ibrahim (2016), the humerus is catalogued as FSAC-KK 01, and is said to be restored to a length of 1.5 meters based on what appears to be Paralititan's complete humerus. However, I'm not sure how they got it that short based on the Paralititan humerus; judging by the figures in the paper, the minimum midshaft width of FSAC-KK 01's humerus is slightly over 26 cm (about 26.03 to be more precise). Meanwhile, according to Gonzalez-Riga (2016), the minimum midshaft width of Paralititan's humerus is 23.4 cm, and the scalebars in Ibrahim (2016) are in agreement with this. So judging by that, at least when based on Paralititan's humerus, FSAC-KK 01 is 1.88 meters long, beating the previous record holder I mentioned on this page earlier. And obviously, it'd be pretty big as well - the only question left is what to use as a base for it. As for that, I think animals like Antarctosaurus and Alamosaurus would be reasonable bases for it, since the titanosaurs figured in the paper were described as similar to derived lithostrotians like Baurutitan, who in turn is related to the more complete Antarctosaurus and Alamosaurus. First off, the Antarctosaurus base. The humerus of MACN 6904 is 107.9 cm long based on Ornithopsis' skeletal, and based on the estimations for the larger specimen FMNH 13019 in Mazzetta (2004), it would weigh about 14.4 tonnes assuming a 1.39 meter femur. Considering this, as well as Thomas Holtz's estimate of 18 meters, FSAC-KK 01 ends up at 31.4 meters and 76.2 tonnes based on Antarctosaurus wichmannianus, which is in the same general size class as the largest specimens of Antarctosaurus. The Alamosaurus base would be similarly sized to that as well. The humerus of USNM 15560 is 1.36 meters long according to Gonzalez-Riga (2016), and Randomdinos estimates the similarly sized BIBE 45854 at 23.5 meters and 29 tonnes. Based on those, FSAC-KK 01 ends up at 32.5 meters and 76.6 tonnes, comparable to the biggest specimens of Alamosaurus. Either way, it looks as though if these bases are reasonably accurate, this humerus is easily among the largest dinosaurs ever. The giant ulna: As stated previously, the humerus isn't the only giant titanosaur specimen from Kem Kem. There is also a very large proximal ulna (UCRC PV9) described in Ibrahim (2020), and it is 54 cm across the proximal end. It's not clear what this is closest to, so I'll tentatively use 3 relatively complete titanosaurs to estimate its general ballpark sizewise. And it stacks up very favorably against them, as can be seen below: -Malawisaurus: 16.7 cm proximal ulna width, 3.25 tonnes following Palaeozoologist's estimate with some extra meat. Given those measurements and the length estimate of 11 meters, the giant ulna ends up at 35.6 meters long and 109.9 tonnes. -Futalognkosaurus: 38.3 cm proximal ulna width based on SpinoInWonderland's skeletal, 38.1 tonnes following Benson (2014). Given those measurements and SpinoInWonderland's length estimate of 23.6 meters, the giant ulna ends up at 33.3 meters long and 106.8 tonnes. -Antarctosaurus: 28.5cm proximal ulna width based on Ornithopsis' skeletal, 14.4 tonnes based on Mazzetta (2004), and 18 meters following Thomas Holtz. Given those measurements, the giant ulna ends up at 34.1 meters long and 98 tonnes. All things considered, this animal appears to be absolutely enormous - it's very likely larger than FSAC-KK 01, and could plausibly surpass the 100 tonne mark. And yes, both were almost certainly larger than known specimens of Paralititan.
A brontomerus giving a hard time to a lone raptor which coveted its cub...
Unlikely (how a lone raptor would be able to to that ? Where is the pack ?). Did the herbivorous female dinosaurs protect efficiently their cubs ?
There's recently been a new giant sauropod dinosaur found in Argentina. The paper is still in press and the animal doesn't have a name, but it looks like we have found one of the largest land animals of all.
Quote:One of the most fascinating research topics in the field of sauropod dinosaurs is the evolution of gigantism. In the particular case of Titanosauria, the record of multi-ton species (those exceeding 40 tons) comes mainly from Patagonia. The record of super-sized titanosaur sauropods has traditionally been extremely fragmentary, although recent discoveries of more complete taxa have revealed significant anatomical information previously unavailable due to preservation biases. In this contribution we present a giant titanosaur sauropod from the Candeleros Formation (Cenomanian, circa 98 Ma) of Neuquén Province, composed of an articulated sequence of 20 most anterior plus 4 posterior caudal vertebrae and several appendicular bones. This specimen clearly proves the presence of a second taxon from Candeleros Formation, in addition to Andesaurus, and is here considered one of the largest sauropods ever found, probably exceeding Patagotitan in size. While anatomical analysis does not currently allow us to regard it as a new species, the morphological disparity and the lack of equivalent elements with respect to coeval taxa also prevent us from assigning this new material to already known genera. A preliminary phylogenetic analysis places this new specimen at the base of the clade leading to Lognkosauria, in a polytomy with Bonitasaura. The specimen here reported strongly suggests the co-existence of the largest and middle-sized titanosaurs with small-sized rebbachisaurids at the beginning of the Late Cretaceous in Neuquén Province, indicating putative niche partitioning. This set of extremely large taxa from Patagonia has contributed to a better understanding of the phylogenetic relationships of titanosaurs, revealing the existence of a previously unknown lineage and shedding new light on body mass evolution. IMO, this is very likely to be the same animal as whatever MUCPv-251 (as was posted earlier) is, but we can't confirm that until we have overlapping material. There is absolutely no shortage of these monster sauropods from Argentina and I am certainly not complaining.
Was able to get my hands on an abstract from the new paper about the giant sauropod. Size estimates can now be made because measurements have been given.
Quote:As MOZ-Pv 1221 lacks humerus and femur, estimates of its body mass cannot be estimated using the current main methods (e.g., Campione and Evans, 2012, 2020; Benson et al., 2014; Bates et al., 2016; Campione, 2017; Otero et al. 2019), precluding direct body mass comparisons with other gigantic titanosaurs for which estimates have been made, both by volumetric and scaling methods, such as Dreadnoughtus and Patagotitan (Benson et al., 2014; Bates et al., 2015; Carballido et al., 2017; Campione and Evans, 2020). In comparison to giant titanosaurs, however, the recovered appendicular bones of MOZ-Pv 1221 are larger than any known titanosaur described to date. The maximum dorsoventral height at the proximal section of the scapula (130 cm) is 17% higher than in Patagotitan (Otero et al., 2020), 26% higher than in Dreadnoughtus (Ullmann and Lacovara, 2016), 130% higher than in Mendozasaurus (González Riga et al., 2018), and 94% higher than in Drusilasaura (Navarrete et al., 2011). The maximum proximodistal length of the pubis of MOZ-Pv 1221 is 166 cm, which is 10% longer than in Patagotitan, 18% longer than in Dreadnoughtus, and 21% longer than in Futalognkosaurus. At present there is no reliable information for comparison with other giants such as Puertasaurus and Argentinosaurus. So although it is not currently possible to estimate the body mass of MOZ-Pv 1221 (limb bones having been found but not excavated), it is clear that the titanosaur partially recovered from the Candeleros Formation can be considered one of the largest titanosaurs, probably of a body mass comparable to Patagotitan or Argentinosaurus or even larger. The best species used in these comparisons for size estimations are probably Patagotitan, Dreadnoughtus, and Futalognkosaurus, due to their completeness. Estimates will be listed in order of comparisons with said species in the above quote. Was MOZ-Pv 1221 really that much bigger than Patagotitan? Scapula 17% taller dorsoventrally? Check. As per Page 8 and Table 2 of Otero et al. (2020), that measurement in the Patagotitan holotype is 111 cm. Pubis 10% longer proximodistally? Check. Table 2 of Otero et al. gives the length of the pubis of the Patagotitan holotype as 150 cm. How big was Patagotitan? As per Larramendi & Paul (2020), sauropods have a higher specific gravity than previously thought. The mean of it would have been 95% as dense as water, as opposed to the 80% as dense as water that Wedel et al. (2005) estimated and that subsequent studies (such as Bates et al. (2016)) have roughly adhered to. Quote:The resulting NSG values in analyzed sauropods range from 0.917 to 0.984. These are significantly higher than estimated by Bates et al. (2016) which included most of the sauropod genera calculated here. They found very low SGs ranging from 0.776 to 0.929 –excluding their minimum convex hull models which further reduce the SGs–. Their low results are because the authors applied an overly low SG of just 1.0 to different apneumatic sections, and estimated extremely large respiratory systems for most of the sample which generally far exceed even what is expected in flying birds in a neutral state. Because the poorly pneumatized vertebrae of dicraeosaurids, the species in this clade were found to be the densest (Table 10), while the lowest NSG were found in the sauropods with the longest necks like mamenchisaurids, Giraffatitan, Barosaurus and Euhelopus with a NSG approaching to 0.93 in some cases. Colossal sized titanosaur carrying relatively large necks (Paul, 2019), were probably in this region (Table 10), or slightly below because their very wide torsos may have allowed them to possess relatively larger respiratory systems. If the lesser density of the neck of the neck relative to the rest of the body is not taken into account when calculating total BM, the later will be overestimated by up to ~3% among very large necked sauropods such as mamenchisaurs and brachiosaurs relative to short necked examples such as shunosaurs. The BM results herein are ~5-12% higher than for the same specimens volumetrically massed by Paul (2016, 2019) for the same specimens due to the lower NSGs used in those efforts. Applying this mean to the older, low-density estimates (such as randomdinos' 55000 kg estimate) gives us an estimate of 65300 kg for the weight of the Patagotitan holotype, and SpinoInWonderland estimates it at 30.8 meters long. How big was MOZ-Pv 1221 based on these estimates for Patagotitan? Scapula based estimate: Given the respective dorsoventral scapula heights of 130 and 111 cm for MOZ-Pv 1221 and Patagotitan, we can estimate MOZ-Pv 1221 at 36.1 meters in length and 104900 kg in weight based on the above. Pubis based estimate: Given the respective proximodistal pubis lengths of 166 and 150 cm for MOZ-Pv 1221 and Patagotitan, we can estimate MOZ-Pv 1221 at 34.1 meters in length and 88500 kg in weight based on the above. Mean Patagotitan-based size estimate for MOZ-Pv 1221 is 35.1 meters and 96700 kg. Was MOZ-Pv 1221 really that much bigger than Dreadnoughtus? Scapula 26% taller dorsoventrally? Nope, it's even bigger than that. I don't know where in Ullmann & Lacovara (2016) they got that from, as there is no measurement given for the dorsoventral height of the scapula and that measurement appears to be 99.2 cm based on Figure 2 of Page 5 as well as their given 174 cm measurement for the whole thing, meaning the scapula of MOZ-Pv 1221 is actually 31% taller than that of the Dreadnoughtus holotype. Pubis 18% longer proximodistally? Nope again, it is bigger than that too. Lacovara et al. (2014) gives the proximodistal pubis length of the Dreadnoughtus holotype at 126 cm with the other linked paper on the animal giving nothing contradicting this, so I don't know where Otero et al. (2021) got that MOZ-Pv 1221's pubis was only 18% longer proximodistally than that of the Dreadnoughtus holotype given that everything published suggests it's about 31.7% larger (which is also consistent with the scapula size disparity). How big was Dreadnoughtus? Matt Wedel has done a volumetric model of the Dreadnoughtus holotype and got a total of 51 cubic meters, but the 32-cubic meter torso is probably some 15-20% too long and chopping the mean (17.5%) of this off it gives us slightly over 46.2 cubic meters for the corrected model. Based on the new mean density from Larramendi et al. outlined above, we can estimate its mass at 44000 kg, and SpinoInWonderland estimates its length at 27.6 meters. How big was MOZ-Pv 1221 based on these estimates for Dreadnoughtus? Scapula based estimate: Given the respective dorsoventral scapula heights of 130 and 99.2 cm for MOZ-Pv 1221 and the Dreadnoughtus holotype, we can estimate MOZ-Pv 1221 at 36.2 meters in length and 99000 kg in weight based on the above. Pubis based estimate: Given the respective proximodistal pubis lengths of 166 and 126 cm for MOZ-Pv 1221 and the Dreadnoughtus holotype, we can estimate MOZ-Pv 1221 at 36.4 meters in length and 100600 kg in weight based on the above. That this estimate ended up so close to the scapula-based estimate is certainly pleasing. Mean Dreadnoughtus-based size estimate for MOZ-Pv 1221 is 36.3 meters and 99800 kg. Was MOZ-Pv 1221 really that much larger than Futalognkosaurus? Scapula dorsoventral height (bonus)? Nope, the disparity between the dorsoventral scapula heights is the greatest discrepancy of overlapping elements in both. Paleo King's Futalognkosaurus skeletal shows the maximum dorsoventral scapula height of the holotype as 99.1 cm given the scalebar (for those wondering why there was no comparison of scapular height with MOZ-Pv 1221 made in the paper, he used unpublished material), and we therefore get a size difference of more than 31.1% between the scapulae of the Futalognkosaurus holotype and MOZ-Pv 1221, greater than the difference between the proximodistal pubis length of those specimens. Pubis 21% longer proximodistally? Check. Page 4 of Calvo et al. (2007) gives the proximodistal length of the pubis of the Futalognkosaurus holotype as 137 cm. How big was Futalognkosaurus? Benson et al. (2014) estimates the mass of the holotype specimen at 38100 kg, and SpinoInWonderland estimates its length at 23.6 meters. How big was MOZ-Pv 1221 based on these estimates for Futalognkosaurus? Scapula based estimate: Given the respective dorsoventral scapula heights of 130 and 99.1 cm for MOZ-Pv 1221 and the Futalognkosaurus holotype, we can estimate MOZ-Pv 1221 at 31 meters in length and 86000 kg in weight based on the above. Pubis based estimate: Given the respective proximodistal pubis lengths of 166 and 137 cm for MOZ-Pv 1221 and the Futalognkosaurus holotype, we can estimate MOZ-Pv 1221 at 28.6 meters in length and 67800 kg in weight based on the above. Mean Futalognkosaurus-based size estimate for MOZ-Pv 1221 is 29.8 meters and 76900 kg. If these size estimates are accurate, I could not agree more with this statement from the paper, especially the bolded and underlined part: Quote:It is clear that the titanosaur partially recovered from the Candeleros Formation can be considered one of the largest titanosaurs, probably of a body mass comparable to Patagotitan or Argentinosaurus or even larger. |
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