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Why Is the Isle of Wight Rich in Dinosaur Fossils? Some of the first-ever dinosaur bone finds occurred on this British island. Now, researchers are discovering even more. By Joshua Rapp Learn, Discover, July 14, 2023 Yours, Paul H.

Something that has been baffling me for a while is the fate of the European genera of Tyrannosauridae after the Mid Cretaceous. Multiple Tyrannosauridae genera including Proceratosaurus (Tyrannosauridae, England, Great Britain, Middle Jurassic (166 Million Years ago): ironically one of the earliest known Tyrannosauridae from the fossil record currently known), Eotyrannus (Tyrannosauridae, Wessex Formation, Isle of Wight, Early Cretaceous (136.4-125.45 Million Years ago)) and an unnamed Tyrannosauridae genera from Germany (Early Cretaceous (130.0-122.5 Million Years ago)) are known from Mesozoic deposits in Europe dating from the Middle Jurassic up to the Early Cretaceous. Holtz, Thomas (December 1998). "A new phylogeny of the carnivorous dinosaurs". Gaia. 15: 5–61. https://www.geol.umd.edu/~tholtz/gaiaphyl.pdf Hutt, Stephen & Naish, Darren & Martill, David & Barker, Michael & Newbery, Penny. (2001). A preliminary account of a new tyrannosauroid theropod from the Wessex Formation (Early Cretaceous) of southern England. Cretaceous Research. 22. 227-242. 10.1006/cres.2001.0252. https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=242e6d5f962a143900f3c8d2ff5eb20d6fe7482b K.-P. Lanser and U. Heinhofer. (2015). Evidence of theropod dinosaurs from a Lower Cretaceous karst filling in the northern Sauerland (Rhenish Massif, Germany). Palaeontologische Zeitschrift 89:79-94 https://www.semanticscholar.org/paper/Evidence-of-theropod-dinosaurs-from-a-Lower-karst-Lanser-Heimhofer/94860c34dedf8ac6d65759af9725ae76402eef59 But by the Late Cretaceous around 70-66 Million Years ago, they are absent from the fossil record in the region. Instead, the top predators of the region at the time seem to be Abelisaurs and large pterosaurs. Isasmendi, Erik & Torices, Angelica & Canudo, José & Currie, Philip & Pereda Suberbiola, Xabier. (2022). Upper Cretaceous European theropod palaeobiodiversity, palaeobiogeography and the intra‐Maastrichtian faunal turnover: new contributions from the Iberian fossil site of Laño. Papers in Palaeontology. 8. 10.1002/spp2.1419. https://onlinelibrary.wiley.com/doi/full/10.1002/spp2.1419 I’m curious on what could have caused this faunal turnover (especially since that between the Ealy Cretaceous (at the time of the known records of Tyrannosauridae from Europe) and the Late Cretaceous, Europe was basically a series of islands) or if they were still present in Europe during the Late Cretaceous and specimens have yet to be found or properly categorized? What do you guys think?

Not very much is published on rare teeth. I'm trying to compile some information so that collectors have something to look at. Might not get them all the answers but its a start. Any discrepancies seen in this info please let me know. If you see anything published that can add to those listed please let me know. Species included in this topic Neovenator salerii Eotyrannus lengi Megalosaurus bucklandi Proceratosaurus bradleyi Acrocanthosaurus atokensis Deinonychus antirrhopus (Page 2) Duriavenator hesperis (Page 2) Coelophysis bauri (Pg 2 - Link to Triassic) Daemonosasurus chauliodus (Pg2 - Link to Triassic) Tawa hallae (Pg 2 - Link to Triassic) Majungasaurus crenatissimus (Pg 3) Neovenator salerii Formation: Wessex Formation Location: Typically Isle of Wight Characteristics: Some lateral crowns show transverse and/or marginal undulations adjacent to the distal and/or mesial carinae Interdenticular sulci between distal denticles may be present Enamel Surface Texture : "ent" in illustration Mesial crowns have their mesial carina twisting strongly toward lingual side A flattened surface and or depression adjacent to the distal carina on the lingual side : "cos" in illustration Mesial carina not reaching the base on most lateral crowns Mesial denticles are shorter and distal ones Measurements: (From Hendrickx 2019 study) (3 isolated lateral teeth) DSDI: 0.833 to 1.03 (Avg 0.96) Distal Density: 14.5 to 18 / 5mm (Avg 15.8 / 5mm) Mesial Density: 15 / 5mm (Avg 15 / 5mm) Ratio's: CHR 1.5 to 2.2 (Avg 1.8), CBR 0.54 to 0.57 (Avg 0.55) Eotyrannus lengi Formation: Wessex Formation Location: Isle of Wight Characteristics: Slightly twisted mesial carina not extending to the root Distal denticles elongated in lateral teeth DSDI should be > 1.2 Transverse undulations: absent Interdenticular sulci may be present Measurements: (From Hendrickx 2019 study) (One isolated Pre-max tooth) DSDI: 1.06 Distal Density: 14.1 / 5mm Mesial Density: 15 / 5mm Ratio's: CHR: 2.6, CBR: 1.2 Measurements: (From @paulyb135 personal collection) (Isolated Lateral tooth) DSDI: 1.47 Distal Density: 3.4 / 1 m Mesial Density: 5 / 1mm Ratio's: CHR: 2.5, CBR: 0.8 Lateral Tooth Premaxillary Tooth (part of holotype) Megalosaurus bucklandi Formation: Tayton Limestone Location: Stonefield Slate Beds, Oxfordshire, Gloucesters Other Occurrences: Chipping Norton Limestone Formation Sharp's Hill Formation Characteristics: Transverse undulations can be well visible and numerous Interdental sulci can be present on both carinae Mesial denticles larger than Distal denticles (DSDI <.08) in some lateral distal teeth Mesial carina does not reach the cervix in most lateral crowns (Can extend 55 to 65% of crown height) Bilobate denticles can be present in mesial carina (see illustration) The mesial carina on mesial teeth is central located not twisted lingually and the distal carina is also centrally positioned weakly offset labially Measurements: (From Hendrickx 2019 study) (10 teeth, 8 isolated, 1 dentary, 1 maxillary) DSDI: 0.8 to 1.03 (Avg 0.9 ) Distal Density: 8.75 to 20 / 5mm (Avg 13 / 5mm) Mesial Density: 8.5 to 20 / 5mm (Avg 12.1 / 5mm) Ratio's: CHR 1.6 to 2.5 (Avg 2.1), CBR 0.39 to 0.68 (Avg 0.55) Bilobate denticles in Mesial carina Sixth right dentary tooth of Megalosaurus bucklandi Mantell, 1827 (OUMNH J13505), crown (B1 ), mesial (B2 ) and distal (B3 ) denticles in labial views, enamel texture Holotype Tooth Proceratosaurus bradleyi Formation: White Limestone,, Great Oolite Location: Gloucestershire, UK Other Occurrences: Not aware of others Characteristics: Very Fine Serrations on both Carina A basal constriction between crown & root is present in some premaxillary teeth (see photo) Mesial denticles smaller than Distal denticles Teeth are relatively small, holotype (considered late juvenile/subadult) see CH measuremets The premaxillary teeth are asymmetrical in cross section, with the mesial carina being displaced lingually The maxillary teeth are transversely flattened, strongly recurved, and have serrated mesial and distal carinae (see photo) In both the premaxillary and fully erupted maxillary teeth, the anterior carina does not extend all the way to the base of the crown, but ends at approximately half the height Individual denticles are chisel-shaped, rounded, and perpendicular to the long axis Basel ridges are seen on some Premaxillary and dentary teeth (see photo) Measurements: (From Hendrickx 2019 study) (9 teeth, 4 maxillary, 5 dentary, ) DSDI: 1 to 1.5 (Avg 1.28 ) Distal Density: 22 to 26 / 5mm (Avg 25.5 / 5mm) Mesial Density: 30 to 37.5 / 5mm (Avg 34 / 5mm) Ratio's: CHR 1.8 to 2 (Avg 1.9), CBR 0.5 to 0.8 (Avg 0.6) Crown Height (CH) Premaxillary teeth (5.3 to 6.7 mm), Maxillary teeth (4 to 12.7 mm), Dentary (4.2 to 11 mm) Reference is 4 good source of information Basal constriction Premaxillary tooth Ridges seen on some Premaxillary and Dentary Teeth Maxillary Teeth Anterior Dentary Teeth Acrocanthosaurus atokensis Formation: Antler Formation, Trinity Group Location: McCurtain County, Oklahoma (Study Group) Other Occurrences: Twin Mountains Formation (Trinity Group), Texas Arundel Formation, Maryland Cloverly Formation, Wyoming Cedar Mountain Formation, Utah* * Acrocanthosaurus sp.. tooth morphology not described. Please note it illegal to sell/purchase these teeth if found on State or Park land Characteristics: Apical denticulation (Contiguous keels with denticles continuing over the tip) (Lipka paper) Distal denticles perpendicular to axis Mesial denticles inclined to axis Transverse and marginal undulations can be present Mesial carina does not reach the base in most crowns Interdenticular sulci not evident Braided enamel (Not sure if its on all or some crowns) Measurements: (From Hendrickx 2019 study) Premaxillary teeth (4) DSDI: 1.3 to 1.5 / 5mm (Avg 1.45 / 5mm) Distal Density: 11.5 to 13.3 / 5mm (Avg 12.5 / 5mm) Mesial Density: 17 to 19 / 5mm (Midline Avg 18 / 5mm) (Apically Avg: 13.3 / 5 mm) Ratio's: CHR: 2.2 to 2.6 (Avg 2.4), CBR: 0.58 to 1 (Avg 0.76) Maxillary teeth (11) DSDI: .73 to 1.2 / 5mm (Avg 0.97 / 5mm) Distal Density: 11.5 to 15 / 5mm (Midline Avg 13.7 / 5mm) (Apically Avg: 11.7 / 5 mm) Mesial Density: 17 to 19 / 5mm (Midline Avg 18 / 5mm) (Apically Avg: 13.3 / 5 mm) Ratio's: CHR: 2.0 to 2.6 (Avg 2.3), CBR: 0.5 to 0.67 (Avg 0.58) Dentary teeth (17) DSDI: 0.83 to 1.0 / 5mm (Avg 0.95 / 5mm) (only 6 teeth) Distal Density: 12.5 to 16 / 5mm (Midline Avg 14.3 / 5mm) (Apically Avg: 12.7 / 5 mm) Mesial Density: 11.8 to 16.2 / 5mm (Midline Avg 11.7 / 5mm) (Apically Avg: 13.4 / 5 mm) Ratio's: CHR: 1.3 to 2.8 (Avg 2.1), CBR: 0.48 to 0.9 (Avg 0.61) Maxillary Jaw (#1 to 4) showing : tun: transverse undulations mun: marginal undulations dca: displaced carina Scale: 1 cm Maxillary tooth (#6) with mun and tun Scale: 1 cm Braided enamel texture on isolated tooth Believe these are distal denticles Scale: 1 mm Reference Material: (1)Hendrickx et al : Dental features in theropods 2019 https://palaeo-electronica.org/content/2019/2806-dental-features-in-theropods (2)Hendrick et al : Taxonomic identification of isolated theropod teeth: The case of the shed tooth crown associated with Aerosteon https://www.sciencedirect.com/science/article/abs/pii/S0195667118303860?via%3Dihub (3)Hendrick et al. : The Dentition of Megalosaurid Theropods https://bioone.org/journals/acta-palaeontologica-polonica/volume-60/issue-3/app.00056.2013/The-Dentition-of-Megalosaurid-Theropods/10.4202/app.00056.2013.full (4)Oliver Rauhut et al Cranial osteology and phylogenetic position of the theropod dinosaur Proceratosaurus bradleyi (Woodward, 1910) from the Middle Jurassic of England 2008 (5)Thomas Lipka The affinities of the enigmatic theropods of the Arundel Clay Facies

Hi, Thought that I might share a little head study of Eotyrannus (T.Rex's great great great grandpa in terms of evolution) this is a small part of a lot of commissions that me and a professional paleontologist are collaborating and working on together as a team. We are especially fond of dinosaurs found on our home turf (the UK specifically the Isle Of Wight). So he wanted to see Eotyrannus recreated and this is the first illustration that I came too, there is a lack of Eotyrannus material, but I got the privilege of handling the real material that's kept safely under lock and key (thank god that I didn't drop it). (- Because there is so little of Eotyrannus found, some of this reconstruction is based on the Dilong which is a similar tyrannosaur that lived around the same time as Eotyrannus and they shared a few similarities in anatomy and possibly environment.) Anyway I hope that a few people like this little study I hope to upload more later on! - Beth